I am afraid somethings wrong there
You should get suspiscious because of d).
It is ,
What does that mean? Well, it's like the intervall
x should be smaller than pi. Minus 50013 is smaller than pi, isn't it?
is similar to
e < pi, so B u C = IR
because A is defined for all x > 0
The set B is defined for all x > e
A without B = (0, e), e. g.
Edit: Ops, that would be I'm sorry, I used the wrong definition of B
Note that pi > e, so