Step 1: Understanding the Concept:
Shrauta Sutras are part of the 'Kalpa Vedanga' (the limb of the Veda dealing with rituals). They are concise, aphoristic manuals that provide the rules for performing major public and domestic sacrifices (Shrauta Yajnas) as described in the Brahmanas. Each Veda has its own set of Shrauta Sutras because the rituals involve four different types of priests, each specialized in a particular Veda. The Rigveda is the domain of the 'Hotr' priest, and its Shrauta Sutras guide the Hotr in his invocatory duties.
Step 2: Detailed Explanation:
The Rigveda is primarily associated with two major Shrauta Sutras corresponding to its surviving schools: the Ashvalayana Shrauta Sutra and the Shankhayana Shrauta Sutra.
1. Ashvalayana Shrauta Sutra: This belongs to the Ashvalayana branch of the Rigveda. It is the most widely followed manual for Rigvedic rituals today. It consists of 12 chapters and provides detailed procedures for the Seven 'Haviryajnas' (like Agnihotra and Darsha-purnamasa) and the Seven 'Somayajnas' (like Agnishtoma). The text is crucial because it explains how the 'Hotr' priest should recite the 'Shastras' (invocatory litanies) during the sacrifice.
Analysis of incorrect options:
- Katyayana Shrauta Sutra: This belongs to the Shukla (White) Yajurveda (Vajasaneyi Samhita). It is highly technical and followed by the Adhvaryu priests of that branch.
- Vaitana Shrauta Sutra: This is the only Shrauta Sutra of the Atharvaveda. It is unique as it adapts many rituals from the other three Vedas to the Atharvanic context.
- Drahyayana Shrauta Sutra: This belongs to the Samaveda (Ranayaniya branch). It focuses on the chants (Stotras) performed by the Udgatr priests.
Knowing the association between Vedas and their respective Sutras is a fundamental requirement for the Kalpa Vedanga section of the NTA exam. The Ashvalayana is the standard Rigvedic manual. It bridges the gap between the poetic hymns of the Samhita and the mechanical acts of the sacrifice. Its importance lies in its clarity and its role in preserving the ritual application of Rigvedic mantras over thousands of years.
Step 3: Final Answer:
The Shrauta Sutra of the Rigveda is the Ashvalayana Shrauta Sutra. Therefore, option (3) is correct.