The curve \( y(x) = ax^3 + bx^2 + cx + 5 \) touches the x-axis at the point \( P(-2,0) \) and cuts then y-axis at the point \( Q \), where \( y' \) is equal to \( 3 \). Then the local maximum value of \( y(x) \) is :
\( \dfrac{27}{4} \)
\( \dfrac{29}{4} \)
\( \dfrac{37}{4} \)
\( \dfrac{9}{2} \)