If a=1,b=10,c=100, and d=1000, then (a+b+c−d)+(a+b−c+d)+(a−b+c+d)+(−a+b+c+d) is equal to<spanclass=′latex−bold′>(A)</span>1111<spanclass=′latex−bold′>(B)</span>2222<spanclass=′latex−bold′>(C)</span>3333<spanclass=′latex−bold′>(D)</span>1212<spanclass=′latex−bold′>(E)</span>4242