'विद्यार्थी' या जोडशब्दातील पोट शब्द कोणते ते सांगा.

The correct answer is Option B (विद्या + अर्थी).

Key Points:
• This is a classic example of Swar Sandhi (Vowel Sandhi), specifically Dirgha Sandhi (Long Vowel Sandhi).
• Rule: When two homogeneous vowels (Sajatiya Swar) come together, they form the long version of that vowel.
• Here, Vidya (विद्या) ends in 'aa' (आ), and Arthi (अर्थी - one who desires/seeks) begins with 'a' (अ).
• आ + अ = आ. Therefore, विद्या + अर्थी = विद्यार्थी (Seeker of Knowledge).
• Key Takeaway: Vidya (आ) + Arthi (अ) = Vidyarthi (आ).