Lines HK and BC lie in a plane. M is the midpoint of line segment BC, and BH and CK are perpendicular to HK. Then we <spanclass=′latex−bold′>(A)</span>always have MH=MK<spanclass=′latex−bold′>(B)</span>always have MH>BK<spanclass=′latex−bold′>(C)</span>sometimes have MH=MK but not always<spanclass=′latex−bold′>(D)</span>always have MH>MB<spanclass=′latex−bold′>(E)</span>always have BH<BC