If $P_1$ and $P_2$ are two odd prime numbers such that $P_1 > P_2$,then $P_1^2-P_2^2$ is

Question

$\begin{array}{1 1}(A) \;\text{an even number}\\(B)\;\text{an odd number} \\(C)\;\text{an odd prime number} \\(D)\;\text{a prime number} \end{array}$