since there is only one choice.

因为只剩下一个选项了
I claim that D is going to be ES, but let's just prove it.

D是ES的我们不妨来证明一下
So is it going to be the case that

那这种情况会不会导致这样的结果
these mutants will eventually take over the whole population

即最后整个种群都是这种突变个体
and everyone will end up looking like a T.A. and being uncooperative?

而每个个体都会像助教那样不合作
So they're busily asexually reproducing all the time,

也就是说它们无时无刻不在疯狂的繁殖
they get bigger and bigger,

它们的数量越来越多
and isn't it in fact the case that

这是不是就是说如果它们
once they've conquered everything that they're ES?

战胜了所有的其他个体它们就是ES呢
So is defect ES in this game?

这个博弈中背叛是ES策略吗
To figure that out we have to do exactly the reverse experiment.

想要弄清楚这一点我们得做一次反向实验
So the experiment now is imagine everyone in the population, all of you guys,

下面假设种群当中每一个个体