Which river is known for changing its course frequently in Bihar?
Explanation
ng its course and causing floods. The key to this question is the precise association expressed in its wording: “Which river is known for changing its course frequently in Bihar?” The answer Kosi matches that clue directly and is therefore factually appropriate. Option A — Gandak — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. It may be associated with another Bihar-related context, but that broader association does not satisfy this specific wording. Option C — Son — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. It may be associated with another Bihar-related context, but that broader association does not satisfy this specific wording. Option D — Bagmati — is incorrect because it does not match the exact person, district, location, institution, river, event or identifying feature required by the question. It may be associated with another Bihar-related context, but that broader association does not satisfy this specific wording. Bihar GK questions frequently place neighbouring districts, related historical personalities, nearby rivers or institutions from the same field among the options. These distractors can appear convincing because they are genuine names, yet they fail the exact relationship being tested. The correct method is to identify the central clue, match it with the relevant map location, historical period or official designation, and then eliminate every alternative separately. On that evidence, option B is the only complete answer.The Kosi River is notorious for changing its course and causing floods.