Step 1: Understanding the Concept:
The Aitareya Brahmana, belonging to the Rigveda, begins by outlining the procedures for the Soma sacrifice, specifically the 'Dikshaniya Ishti' or the initiation ceremony. This ceremony transforms the mundane sacrificer into a 'consecrated' one. The text provides a theological justification for the deities selected for the offering and simultaneously describes the manual acts of preparing the sacrificial items. This question tests the ability to distinguish between a theological 'why' and a ritualistic 'how'.
Step 2: Detailed Explanation:
Let us analyze Assertion (A). The very first chapter of the Aitareya Brahmana (1.1) declares: "agnirvai devānāmavamo viṣṇuḥ paramaḥ". This states that Agni is the 'lowest' or the first of the gods (at the earth level), and Vishnu is the 'highest' or the supreme (at the celestial level). The text further explains that by offering a cake (Purodasha) to Agni and Vishnu jointly (Agnavishnavam), the sacrificer encompasses all the deities that reside between these two extremities. It is a ritual of 'inclusion' that secures the favor of the entire divine pantheon right at the beginning of the Agnishtoma. Thus, Assertion (A) is a core theological truth of the Rigvedic ritual tradition.
Now, consider Reason (R). In the 'Karmakanda' (ritual procedure), the preparation of the Purodasha involves kneading dough and spreading it across baked clay potsherds (Kapalas). As the priest flattens the dough to form the cake, he recites the mantra "uru prathasva tvaṃ yajñapataye" (Spread out wide for the master of the sacrifice). This mantra, found in the Yajurveda and cited in Brahmanas, is a ritual formula intended to 'expand' the spiritual efficacy of the sacrifice as the cake physically expands. Therefore, Reason (R) is also a factually correct ritual description.
Evaluation of Logical Connection:
To determine if (R) explains (A), we must ask: "Does the act of spreading the cake with a specific mantra explain why the deities chosen for the offering are Agni and Vishnu?" The answer is clearly no. The reason for the Agni-Vishnu dedication is their status as the cosmic boundaries (Avama and Parama). The reason for the "Uru prathasva" mantra is the physical act of preparing the dough. There is no causal or logical link between the rank of the deities and the manual flattening of the cake. These are two independent ritual truths described in the same section of the Brahmana. In competitive exams, such questions test whether the student is simply identifying true statements or actually understanding the internal logical structure of the Vedic texts.
Step 3: Final Answer:
Both Assertion (A) and Reason (R) are factually correct statements according to the Aitareya Brahmana, but (R) provides no explanatory justification for (A). Therefore, the correct option is (2).