Suppose the following theorem is proven using a direct proof.

Theorem: If

$$

is a rational number, then x $^2+5$ is also rational.

What would be assumed at the beginning of the proof?

a$.$ x $=$ a$/$b where a$,$b are integers and b $!=0$

b$.$ x is a real number

c$.$ x is an integer

d$.$ x $^2+5=$ a$/$b where a$,$ b are integers and b $!=0$