Step 1: Understanding the Concept:
The 'Rigveda-bhashya-bhumika' is the comprehensive introductory volume written by Acharya Sayana to his monumental commentary (the Sayana Bhashya) on the Rigveda. In this text, Sayana defends the authority, eternity, and meaningfulness of the Veda against various objections from skeptics and other schools of thought. To establish his arguments on a sound philosophical footing, he frequently relies on the 'Purva Mimamsa Sutras', also known as the Jaimini Sutras. The Mimamsa school is the primary authority on the interpretation of the Vedic ritual commands.
Step 2: Detailed Explanation:
The phrase "Svadhyayavadavachanat" is a logical argument used to prove that the Veda must be studied with its meaning, not just recited mechanically. It is derived from the Vedic injunction "Svadhyayo'dhyetavyah" (One's own branch of the Veda must be studied). Sayana, following Jaimini's logic, argues that if the Veda were merely a string of meaningless sounds used for rituals, the command to "study" it would be illogical. Study ('Adhyayana') implies the comprehension of meaning.
In the Jaimini Sutras (the foundational text of Purva Mimamsa), Jaimini establishes that the Veda is 'Apaurusheya' (not of human origin) and that its purpose is 'Dharma-jijnasa' (the inquiry into duty). The specific argument "Svadhyayavadavachanat" is part of the debate against those who claimed that Vedic mantras are 'Nirarthaka' (meaningless). Sayana uses this Mimamsa principle to demonstrate that because the Veda itself prescribes its own study, it implicitly asserts that it contains meaningful knowledge meant to be understood by the student.
Acharya Sayana's 'Bhumika' is essentially a synthesis of Vedic tradition and Mimamsa logic. By quoting Jaimini, he provides a 'Shastric' (scriptural) justification for why a word-for-word commentary (like his own) is necessary and sanctioned by the tradition itself. For students of the NTA exam, the Rigveda-bhashya-bhumika is a critical text, and identifying the sources of its major logical proofs (like those from the Mimamsa Sutras) is a key requirement for success. This highlights the intersection of Vedic Samhitas and the Darsanas (Philosophical schools).
Step 3: Final Answer:
The sentence is quoted from the Jaimini Sutra. Thus, option (1) is correct.