Kermit writes down the numbers 1, 2, 3, 4, 5. He then erases one number, and discovers that the sum of the remaining numbers is 13. Which number was erased?<spanclass=′latex−bold′>(A)</span>1<spanclass=′latex−bold′>(B)</span>2<spanclass=′latex−bold′>(C)</span>3<spanclass=′latex−bold′>(D)</span>4<spanclass=′latex−bold′>(E)</span>5