Vedic Literature

Step 1: Understanding the Concept:
The question asks to identify the person who posed the foundational question in the Mundaka Upaniṣad to the sage Aṅgiras. This question sets the stage for the entire philosophical discourse of the text.
Step 2: Detailed Explanation:
The Mundaka Upaniṣad opens by establishing its lineage of knowledge. It then states that a great householder (mahāśāla) named Śaunaka duly approached the sage Aṅgiras and asked the profound question: "kasmin nu bhagavo vijñāte sarvamidaṃ vijñātaṃ bhavatīti" which translates to "Revered sir, what is that by knowing which all this becomes known?".
This question prompts Aṅgiras to explain the two kinds of knowledge: the lower (Aparā Vidyā - the Vedas, grammar, etc.) and the higher (Parā Vidyā - the knowledge of the imperishable Brahman).
The other individuals are famous figures from different Upanishads:


Uddālaka and his son Śvetaketu are central figures in the Chāndogya Upaniṣad, known for the "Tat Tvam Asi" dialogue.
Janaka, the king of Videha, is a prominent philosopher-king in the Bṛhadāraṇyaka Upaniṣad.

Step 3: Final Answer:
It was Śaunaka who approached Aṅgiras with this question in the Mundaka Upaniṣad. Therefore, option (2) is correct.

Step 1: Understanding the Concept:
The question asks to identify the source of a specific quote that uses an analogy of words and their union to describe the process of education involving a teacher, a pupil, and knowledge. This metaphorical style is characteristic of the Upanishads.
Step 2: Detailed Explanation:
The quote is a direct reference to a passage in the Taittirīya Upaniṣad. Specifically, it is from the third Anuvāka (section) of the first chapter, known as the Śikṣā Vallī (Chapter on Instruction).
In this section, the Upanishad presents a series of "great connections" (mahāsaṃhitāḥ) through analogies. The passage mentioned in the question is one such analogy, where:


The teacher (ācārya) is the first form (pūrvarūpam).
The pupil (antevāsī) is the latter form (uttararūpam).
Knowledge (vidyā) is their junction (sandhiḥ).
Instruction (pravacanam) is the connection (sandhānam).
This illustrates the sacred and interconnected nature of the teaching-learning process. The other texts listed do not contain this specific formulation.
Step 3: Final Answer:
The quote is explicitly from the Śikṣā Vallī of the Taittirīya Upaniṣad. Therefore, option (2) is correct.