设Ω是由曲面x²+y²=R²>及z=0，z=1所围区域，则三重积分=∫∫∫_Ωf(x²+y²)dυ在柱坐标下化为累次积分为()

设Ω是由曲面x²+y²=R²>及z=0，z=1所围区域，则三重积分=∫∫∫_Ωf(x²+y²)dυ在柱坐标下化为累次积分为()

A.4∫₀^πdθ∫₀^Rdr∫₀¹f(r²)rdz

B.4∫₀^πdθ∫₀¹dr∫₀^Rf(r)rdz

C.∫₀^2πdθ∫₀^Rdr∫₀¹f(r)rdz

D.∫₀^2πdθ∫₀¹dr∫₀^Rf(r)rdz

正确答案是C