The first commission of India also adhered to

The correct answer is The three-language formula.

To understand why, let us explore the historical and educational context of this question in detail.

Background: Education Commissions in India
After India's independence in 1947, the government recognized the urgent need to restructure the national education system. The first major step in this direction was the establishment of the University Education Commission (1948–1949), also known as the Radhakrishnan Commission, chaired by Dr. S. Radhakrishnan. However, when we refer to the "first commission" specifically in the context of school education and language policy, we are referring to the Kothari Commission (1964–1966) — formally known as the Education Commission of India — which was the first comprehensive national education commission covering all levels of schooling.

What is the Three-Language Formula?
The Three-Language Formula is a language education policy recommended for school-level education in India. It prescribes that students should learn three languages during their schooling:

1. The regional language (or the mother tongue of the student)
2. Hindi (the official language of the Union, especially for non-Hindi-speaking states)
3. English (or another modern Indian or foreign language, especially for Hindi-speaking states)

Why did the First Commission adhere to the Three-Language Formula?
India is an extraordinarily diverse country with hundreds of languages and dialects. A single-language or two-language formula would have either ignored regional linguistic identities or failed to prepare students for national and international integration. The Kothari Commission (1964–66) strongly endorsed and elaborated upon the three-language formula, which had already been discussed in the 1956 Official Language Commission's recommendations and the National Integration Council's deliberations.

The rationale behind the formula was threefold:

• Preserving regional identity: By including the mother tongue or regional language, students remain connected to their cultural and linguistic heritage.
• National unity: Learning Hindi (for non-Hindi speakers) or another Indian language (for Hindi speakers) promotes national integration and communication across state boundaries.
• Global access: English equips students with international communication skills essential for higher education, science, and global participation.

The Commission's Recommendation in its Own Words:
The Kothari Commission explicitly recommended that the three-language formula be implemented uniformly and sincerely across all states. It recognized that a uniform language policy was essential for India's cohesion, and that no single language could or should dominate to the exclusion of others. This balanced approach — honoring the mother tongue, the national link language, and a modern language — made the three-language formula the pedagogical cornerstone of Indian school education.

Why Not the Other Options?

• The one-language formula would have neglected either regional identity or national integration — clearly insufficient for India's diversity.
• The two-language formula would have served some needs but still left a gap — either ignoring the regional language or the link language.
• The four-language formula was never formally endorsed, as adding a fourth language would impose an excessive burden on students without proportional benefit.

Conclusion:
The first commission of India (Kothari Commission) adhered to the three-language formula because it offered the most balanced, inclusive, and educationally sound approach to language learning in a multilingual, multicultural nation like India. It respected regional diversity, promoted national unity, and ensured global competitiveness — all at once.