Choose the correct pair of hormones which interact with membrane-bound receptors.

Steroid hormones work as:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: $FSH$,which interacts with membrane-bound receptors,does not enter the target cell.
Reason $(R)$: Binding of $FSH$ to its receptors generates a second messenger (cyclic $AMP$) for its biochemical and physiological responses.
In the light of the above statements,choose the most appropriate answer from the options given below:

Cyclic adenosine monophosphate $(cAMP)$ was discovered by

Illustrate the differences between the mechanism of action of a protein and a steroid hormone.

Find out the odd one with respect to chemical nature$-$