5 单选(4分)下列不等式不成立的是 () .-|||-○A. (int )_(0)^pi (e)^-(x^2)(cos )^2xdxgt (int )_(pi )^2pi (e)^-(x^2)(cos )^2xdx-|||-○ B. (int )_(2)^3(x)^2dxlt (int )_(2)^3(x)^3dx-|||-o C. (int )_(0)^1(e)^-(x^2)dxlt (int )_(0)^1(e)^-xdx-|||-D D. (int )_(0)^1xdxgt (int )_(0)^1ln (1+x)dx