A rectangular field is 80 m long and 60 m wide. If fence posts are placed at the corners and are 10 m
apart along the 4 sides of the field, how many posts are needed to completely fence the field?<spanclass=′latex−bold′>(A)</span>24<spanclass=′latex−bold′>(B)</span>26<spanclass=′latex−bold′>(C)</span>28<spanclass=′latex−bold′>(D)</span>30<spanclass=′latex−bold′>(E)</span>32