Answer
b), c) and d) are violated.
Work Step by Step
a) The conservation of energy states that $$\frac{1}{2}m(v_f^2-v_0^2)=mg(h_0-h_f)$$
As he hovers in mid air, his height does not change, so $(h_0-h_f)=0$, so $(v_f^2-v_0^2)=0$, or $v_f=v_0$, which makes sense because Superman is stationary the whole time. So this law is not violated.
b) To throw the villain forward, Superman has to apply a force $F$. However, according to Newton's 3rd law, this means Superman undergoes a reaction force $-F$. And according to Newton's 2nd law, $$-F=m(-a)$$
or Superman will have an acceleration backward, so he will be pushed backward. The fact that he is still stationary means Newton's 2nd law and 3rd law have been violated.
c) Before Superman throws the villain, they are both stationary, so $\sum p_0=0$
According to the conservation of linear momentum, $$m_{superman}v_{superman}+m_{villain}v_{villain}=0$$ $$m_{villain}v_{villain}=m_{superman}(-v_{superman})$$
In other words, by throwing the villain forward, again Superman has to be pushed backward, so he cannot be stationary. This law is violated, too.
