圖中板和鉚釘為同一材料,已知。為充分提高材料利用率,則鉚釘?shù)闹睆綉撌牵ǎ?img src="https://newimg.ppkao.com/2019-03/wangxuan/201903041630191374.jpg" />
A.A B.B C.C D.D
A.2 B.4 C.8 D.16