Question

Can someone please help??
The question is:

Given

a= O with a line through it
b=B
c= then A union B=B
d=A
e=then A intersection B=B
The choices are:
1. If A (sideways U) B
2. If B (sideways U) A
3. A union (O with alone through it)
4. A intersection (O with a line through it)
5. B union (O with a line through it)