Who can help with my trig

This has nothing to do with trigonometry.

is notation for the quotient of the two functions . In other words,

The domain is the set of values of such that this quotient is defined. In particular, the function is defined as long as the denominator is not 0. This happens for

so can be any value except these two. In interval notation, the domain would be

so the answer is B (the second option).