For each positive integer m>1, let P(m) denote the greatest prime factor of m. For how many positive integers n is it true that both P(n) \equal{} \sqrt{n} and P(n \plus{} 48) \equal{} \sqrt{n \plus{} 48}?
<spanclass=′latex−bold′>(A)</span>0<spanclass=′latex−bold′>(B)</span>1<spanclass=′latex−bold′>(C)</span>3<spanclass=′latex−bold′>(D)</span>4<spanclass=′latex−bold′>(E)</span>5