Select the correct answer in each of the following:
\left(3q+7p^2-2r^3+4\right)-\left(4p^2-2q+7r^3-3\right)=?
(a)\left(p^{2}+2 q+5 r^{3}+1\right)
\text { (b) }\left(11 p^{2}+q+5 r^{3}+1\right)
(c)\left(-3 p^{2}-5 q+9 r^{3}-7\right)
(d)\left(3 p^{2}+5 q-9 r^{3}+7\right)