Question

There is only room for one more person in the back seat of the car _____ my aunty is too fat.
because/ because if/ because of/because for

Answer 1

The answer to this question will be "Because". There is only room for one more person in the back seat of the car because my aunty is too fat.

In the sentence because acts as a coordinating conjunction connecting two important information and i.e. only room for one person and my aunty is fat.