Let \left(a_{n} \right)_{n \equal{} 1}^{\infty } be a sequence on real numbers such that a{}_{n \plus{} 1} \equal{} a_{n} a_{n \plus{} 2} for every n≥1. The number of elements in the set {an:n≥1} cannot be<spanclass=′latex−bold′>(A)</span>2<spanclass=′latex−bold′>(B)</span>3<spanclass=′latex−bold′>(C)</span>4<spanclass=′latex−bold′>(D)</span>5<spanclass=′latex−bold′>(E)</span>None