Step 1: Concept Identification: The objective is to discern accurate statements concerning ancient inscriptions, which serve as primary historical sources.
Step 2: Detailed Analysis:
(A) Routine agricultural practices and events of daily life are the subject-matter of inscriptions: Generally inaccurate. Due to the cost and permanence of inscriptions, they typically documented significant matters like royal decrees, temple donations, land grants, or military victories, rather than everyday occurrences.
(B) Record the achievements, activities or ideas of those who commissioned them: Correct. This was the primary function. For instance, Ashoka's inscriptions conveyed his Dhamma principles, and Prashastis detailed royal accomplishments.
(C) Writings are engraved on hard surfaces such as stone, metal or pottery: Correct. This defines an inscription (epigraph). The use of durable materials ensured their long-term preservation.
(D) The earliest inscriptions were in Prakrit: Correct. The earliest significant historical inscriptions in India, Emperor Ashoka's edicts (3rd century BCE), were written in various Prakrit dialects, the common vernacular of the populace at the time.
Step 3: Conclusion: Statements (B), (C), and (D) are accurate; statement (A) is inaccurate. Therefore, option (4) is the correct selection.