Let y=(x−a)2+(x−b)2,a,b constants. For what value of x is y a minimum?<spanclass=′latex−bold′>(A)</span>2a+b<spanclass=′latex−bold′>(B)</span>a+b<spanclass=′latex−bold′>(C)</span>ab<spanclass=′latex−bold′>(D)</span>2a2+b2<spanclass=′latex−bold′>(E)</span>2aba+b