46. 下列烷類分子的 IUPAC 系統命名為何？ (A) 2,2,6-trimethyl-4,5-dipropyloctane (B) 4-sec-butyl-5-neopentyloctane (C) 4-neopentyl-5-sec-butyloctane (D) 4,5-dipropyl-2,2,6-trimethyloctane