48. 下列何者其上皮細胞具刷狀緣 (brush border)? (A) 近曲小管 (proximal convoluted tubule) (B) 遠曲小管 (distal convoluted tubule) (C) 亨氏襻細肢 (thin limb of Henle's loop) (D) 乳突管 (papillary duct)