Hello!

I am afraid somethings wrong there

Yes!

No!

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

Yep, that's correct.

because A is defined for all x > 0

The set B is defined for all x > e

so

A without B = (0, e), e. g.

Edit: Ops, that would be I'm sorry, I used the wrong definition of B

B = (0, e)

Note that pi > e, so

That's why