It's because of "A."全都因为A

because of:因为； 由于

The war was lost because of a shortage of munitions.

战争因军火不足而失败。

It's not me I'm worried about.我担心的不是自己

worry about:担心； 烦恼

Don't worry about little things.

别为琐事烦恼。

we look guilty as hell.看上去就像我们是凶手

as well:也；又

Tom is very unfriendly to me as well.

汤姆对我也很不友善。

That's what you were arguing about this morning.这就是今早你跟她们吵的原因

argue about:讨论(议论)

I'm not going to argue about this.

我不想争论这个问题。

The couple begin to argue about money.

夫妇俩开始为钱争吵。

They'll figure it out. 她们会弄清楚的

figure out:想出；解决

I can't figure out why he is absent.

我弄不明白他为什么缺席。

She couldn't figure out who put a tail on her.

她猜不透谁派人盯她的梢。