A.6fff\(\pi\)/ffffff\(r^2\)/fff+4fff\(\pi\)/fffr
B.7fff\(\pi\)/ffffff\(r^2\)/fff
C.8fff\(\pi\)/ffffff\(r^2\)/fff
D.3fff\(\pi\)/ffffff\(r^2\)/fff+2fff\(\pi\)/ffffff\(r^{2}\)/fff
E.3fff\(\pi\)/ffffff\(r^3\)/fff+4fff\(\pi\)/fffr
我的答案：
