If the $P^{th}$ term of an A.P. is $q$ and the $q^{th}$ term is $p$ then its $n^{th}$ term is ______

Question

$\begin{array}{1 1}(A) \; p-q+n\\(B)\;p+q-n\\(C)\;p-q-n\\(D)\;p+q+n\end{array}$