Cho \(\int\limits_0^3 {2f\left( x \right){\rm{d}}x} = \int\limits_0^2 {3{x^2}dx} \) và \({\rm{ }}\int\limits_0^3 {g\left( t \right){\rm{dt}}} = - 1\), khi đó \(\int\limits_0^3 {\left[ {f\left( x \right) + 3g\left( x \right)} \right]{\rm{d}}x} \) bằng
A.\(4\).
B.\(7\)
C.\(1\) .
D.\(3\).