Answer
(b) is the correct answer.
Work Step by Step
Let's call the pushing force $P$ and the angle $P$ makes with the wall $\theta$. We have the horizontal component of $P$ is $P\sin\theta$
As $P\sin\theta$ pushes horizontally onto the wall, according to Newton's 3rd law, the wall pushes back onto the person with normal force $F_N$. Also, with Newton's 3rd law, we have $$P\sin\theta=F_N$$
Here, the angles are ranked in ascending order: $\theta_B\lt\theta_A\lt\theta_C$
Since $P\sin\theta=F_N$, we can rank $F_N$ in ascending order, too: B, A, C.
