某DNA分子含有碱基A对,腺嘌呤m个,将该DNA分子用15N进行标记,让其进行复制,则在第n次复制中需要消耗环境中游离胞嘧啶脱氧核苷酸个数为( )
A:(A–m)(2n–1)
B:(A/2 –m)2n–1
C:(A–m)(2n–1–1)
D:(A–m)2n–1