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.