Which of the following expressions represents the indefinite integral of f(x)=3x2+exf(x) = 3x^2 + e^xf(x)=3x2+ex?
x3+ex+Cx^3 + e^x + Cx3+ex+C
9x+ex+C9x + e^x + C9x+ex+C
x3+xex+Cx^3 + xe^x + Cx3+xex+C
3x3+ex+C3x^3 + e^x + C3x3+ex+C