tim never reads books on history,so it’s for

him to answer these questions A possible Bimpossible C easy D serious 麻烦说一下理由

Tim never reads books on history,so it’s for the reason.（it代指failed the exam）
提姆从来没有读过历史书，这就是没考过的原因。
on history 有关历史的书 做定语，修饰book
in history 在历史上

be for
[英][bi: fɔ:][美][bi fɔr]
拥护，受责备;
1．be in favour of赞成；拥护
I'm for the Conservatives， but she's for the Socialists．我拥护保守党人，但她却拥护社会党人。
2．be going to ； be heading for要去；动身去
I'm for the hills this year．今年我要到山区去。
例句：
If a new leader emerged, it would then be for the Queen to invite him to form a government.
如果新首脑产生了，女王就会邀请他组建政府。
f you're a busy person, looking to meet several potential mates at the same event, speed dating could be for you.
如果你是个忙人，想在同一场合和几位可能成为自己伴侣的人见面，那么快速交友可能就适合你。

我不会~~~但还是要微笑~~~：）