Which ancient sage is credited with composing the foundational Sanskrit text on performing arts known as the 'Natya Shastra'?

The correct option is Bharata Muni.

Step-by-Step Explanation:
1. Understanding the Text: The Natya Shastra is a foundational ancient Sanskrit treatise covering all aspects of performing arts, including theatrical performance, dance, music, gestures, costume design, and stagecraft.
2. Authorship: The text is traditionally attributed to the ancient sage Bharata Muni. It is celebrated for introducing the core theory of Rasa (aesthetic emotions) and Bhava (emotional expressions), which form the bedrock of classical Indian aesthetics.
3. Reviewing Other Options:
• Tulsidas: A prominent 16th-century saint and poet known for writing the Ramcharitmanas.
• Valmiki: The ancient sage and original poet (Adi Kavi) who authored the epic Ramayana.
• Kalidasa: A master playwright and poet of classical Sanskrit literature, famous for works like Abhijñānaśākuntalam and Meghadūta.
4. Conclusion: Hence, the ancient sage credited with composing the Natya Shastra is Bharata Muni.