C-14-Q043mediumsingle_mcqIn △ABC\triangle ABC△ABC, AB=6AB = 6AB=6, AC=4AC = 4AC=4, BC=10BC = 10BC=10. ADADAD bisects ∠A\angle A∠A, meets BCBCBC at DDD. Then BD=?BD = ?BD=?a444b555c666d1010