Step 1: Understanding Rigveda commentaries.
The Rigveda is the oldest Veda, containing over 1000 hymns.
Since its language is archaic, several scholars wrote commentaries (bhāṣyas) to explain the meaning of the mantras.
Among these, the most authoritative and widely accepted commentary is by Sayanacharya.
Step 2: About Sayanacharya.
Sayanacharya (14th century AD) was a minister and scholar in the court of King Bukka of the Vijayanagara Empire.
He, with the support of his brother Madhava, wrote detailed commentaries on almost all four Vedas.
His Rigveda Bhāṣya is considered one of the most comprehensive explanations of Rigvedic hymns.
Step 3: Analysis of options.
- (1) Sayanacharyah: Correct. He is the famous commentator of Rigveda.
- (2) Halayudhah: He was a scholar of Sanskrit grammar and lexicography, not the Rigveda commentator.
- (3) Venkatmadhavah: Known for other scholarly works, not Rigveda commentary.
- (4) Arvindah: Not associated with Rigveda commentary.
Step 4: Conclusion.
Thus, the commentator of the Rigveda is Sayanacharya.