—I’m very sorry, Allen. I can't find your favorite CD.

— _____, Torn. I'll go and buy another one.

A. It doesn't matter            B. Don't say that

C. Sure                         D.  You are kidding.

某课外小组同学使用含某种激素的饲料喂养蝌蚪，缩短了蝌蚪发育成蛙的时间。请问该饲料中所含的激素是[ ]

A．性激素

B．胸腺激素

C．胰岛素

D．甲状腺激素