these 可以做主语吗? Prep2#34

Besides adding complementary flavors to many foods, hot sauces stimulate the release of endorphins in the brain, just as exercise does, and these have a pain-relieving effect like morphine's.

(A) hot sauces stimulate the release of endorphins in the brain, just as exercise does, and these have a pain-relieving effect like morphine's

(B) hot sauces stimulate the release of endorphins in the brain, like exercise, and they have a pain-relieving effect that is like morphine

(C) hot sauces and exercise both stimulate the release of endorphins in the brain, and they have a pain-relieving effect like morphine

(D) the release of endorphins in the brain is stimulated both by hot sauces and exercise, and they have a pain-relieving effect like morphine's

(E) the release of endorphins in the brain is stimulated by hot sauces, just as with exercise, and these have a pain-relieving effect like that of morphine

AB之间:

白勇语法里我记得说these/that/this/这样的词不能单独用来做主语呀?这么看是可以的呀?

请NN们解释一下什么情况下these/those这样的指示代词可以做主语吧~~~~

我用这一点直接把A排除了...很勉强地选了B,但是现在觉得B里面like excercise的位置确实很微妙,而且they指代不明也.说affect that is like morphine也不对....