During fixation of Bennett's fracture, which muscle hinders it :: (A) Extensor pollicis brevis, (B) Flexor pollicis brevis, (C) Flexor pollicis longus, (D) Abductor pollicis longus
Answer is D. Following are the deforming forces in Bennett's fracture :

At the distal fragment, it is the adductor pollicis.
At the proximal fragment, it is the abductor pollicis longus.