8. 的命名為(A) (2R,4S)-5-Mercapto-4-methylpentan-2-ol(B) (2R,4R)-5-Mercapto-4-methylpentan-2-ol(C) (2R,4R)-4-hydroxy-2-methylpentane-1-thiol(D) (2R,4R)-5-thiol-4-methylpentan-2-ol