Concept:
Early Buddhism and Jainism were reform movements that sought to challenge the dominance of Brahmanical traditions, which used Sanskrit—a language largely restricted to the elite and priestly classes.
Step 1: Evaluating Assertion A.
Early Buddhist teachings (like the Tripitakas) and scriptures were primarily composed in Pali, while Prakrit was also widely used in various Buddhist and Jain traditions of that era. Thus, Assertion A is correct.
Step 2: Evaluating Reason R.
Pali and Prakrit were the "Jan Bhasha" or the vernaculars (common spoken languages) of the masses in ancient India, whereas Sanskrit was the "Dev Bhasha" (language of the gods/scholars). Thus, Reason R is correct.
Step 3: Analyzing the Connection.
Lord Buddha deliberately chose to preach and record scriptures in Pali and Prakrit *because* he wanted his message to be accessible to the common man, not just scholars. Therefore, the fact that they were vernaculars directly explains why the scriptures were written in them. R is the correct explanation of A.