Explanation
Bimbisara is the answer that matches the Bihar-specific fact asked in the question. rengthen Magadha's political position. The key to this question is the precise association expressed in its wording: “” The answer Bimbisara matches that clue directly and is therefore factually appropriate. Option A — Ajatashatru — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. Option C — Mahapadma Nanda — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. Option D — Udayin — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. Bimbisara used matrimonial alliances to strengthen Magadha's political position. In ‘Which ancient king of Magadha is credited with strengthening diplomatic relations through matrimonial alliances?’, the decisive clue is the exact place, institution, event, physical feature or administrative category mentioned in the stem.