The 'Mahabhashya', a great commentary on Panini's grammar, was written by:

The "Mahabhashya" ("Great Commentary") is a Sanskrit work on grammar written by Patanjali, probably in the 2nd century BCE.

About the Mahabhashya:

• It is a detailed commentary on selected sutras of Panini's "Ashtadhyayi" and on the "Varttikas" (explanatory notes) of Katyayana.
• It is written in the form of a lively dialogue, with questions, objections and answers, which makes it one of the finest examples of Sanskrit prose.
• It discusses the nature of words, meaning and language, and defends Panini's rules.

It contains incidental historical information. For example, it refers to a sacrifice performed for King Pushyamitra Shunga and to the Greek (Yavana) attacks on Saketa and Madhyamika, which helps historians date events of the post-Mauryan period.

Patanjali is therefore believed to have lived during the reign of Pushyamitra Shunga (about 185-149 BCE).

The "Munitraya" (three sages) of Sanskrit grammar:

• Panini: "Ashtadhyayi".
• Katyayana (Vararuchi): "Varttikas".
• Patanjali: "Mahabhashya".

Patanjali and the Yoga Sutras:

• The "Yoga Sutras", the foundational text of the Yoga school of philosophy, describing the "eight limbs" (ashtanga) of yoga, are also attributed to a sage named Patanjali.
• Indian tradition often regards the grammarian and the author of the Yoga Sutras as the same person, but many modern scholars believe they were different people who lived at different times.

Other important Sanskrit works:

• Bhartrihari: "Vakyapadiya" (philosophy of language) and the "Shatakatraya" (poetry).
• Kautilya (Chanakya): "Arthashastra", a treatise on statecraft and economics.
• Yaska: "Nirukta", an early work on etymology of Vedic words.

Why not the other options?

• ✗Katyayana wrote the "Varttikas" on Panini.
• ✗Bhartrihari wrote "Vakyapadiya".
• ✗Kautilya wrote the "Arthashastra".