71.De Quervain's 肌腱腱鞘炎常見以下那兩條肌腱的發炎?①伸拇短肌(extensor pollicis brevis)② 伸拇長肌(extensor pollicis longus) ③ 外展拇短肌(abductor pollicis brevis)④ 外展拇長肌(abductor pollicis longus) (A)①③ (B)②④ (C) ①④(D)②③