这个是有关于if conditional 的问题，由 if-clause 和 main clause 组成。if clause 就是句子里有if 的部分，main clause 就是有if的部分的前面或后面的部分。
以你给的题目举例子：if........positions (if clause), he.......now (main clause)
有分成四种，就是 zero conditional, first conditional, second conditional 和 third conditional。
Zero conditional 是用来说明 truth 或 facts。它的tense是 (if + present simple, present simple)
例如：if you exercise regularly, you stay in shape.
First conditional 是用来说明很大可能性会发生的事。它的tense是 (if + present simple, will/won't + bare infinitive)
例如：if we do not stay at home, the virus will spread.
Second conditional 是用来说明比较幻想化，或很少几率会发生的事。它的tense是 (if + past simple, would/wouldn't + bare infinitive)
例如：if I had more money, I would travel the world.
Third conditional 是用来说明不可能会发生的事，因为已经过去了。它的tense是 (if + past perfect, would/wouldn't + have + past participle)
例如：if I had not called for an ambulance, she would've died.
所以依照你的问题，它是个third conditional，所以答案是A。
