Which of the following statements are true of languages in India ?
a. English is the official language of India.
b. Hindi is the national language of India.
c. Hindi is the official language of India.
d. English is the associate official language of India.

The correct answer is ‘c’ and ‘d’ are true.

Let us analyze the statements given regarding the languages in India:

Statement a: English is the official language of India.
This statement is inaccurate in calling English the primary official language. According to Article 343(1) of the Indian Constitution, the official language of the Union of India is Hindi in the Devanagari script. Therefore, statement a is false.

Statement b: Hindi is the national language of India.
The Constitution of India does not grant the status of 'National Language' to any single language. While Hindi is widely spoken and serves as an official language, India has 22 languages listed in the Eighth Schedule of the Constitution, but no declared national language. Therefore, statement b is false.

Statement c: Hindi is the official language of India.
According to Article 343(1) of the Indian Constitution, Hindi in Devanagari script is designated as the official language of the Union. Therefore, statement c is true.

Statement d: English is the associate official language of India.
As per the Official Languages Act, 1963, English is designated as the associate official language of India for official transactions of the Union. Therefore, statement d is true.

Hence, statements c and d are true, making the correct option ‘c’ and ‘d’ are true.