Integrate : $\int 5x^2 \tan ^2 (6x^3) dx$

Question

$(a)\;cos (6x^3)+c \qquad(b)\;\sin (6x^3)+c \qquad(c)\;\frac{5}{18} [\cot (6x^3)-(6x^3)]+c \qquad (d)\;\frac{5}{18} [\tan (6x^3)-(6x^3)]+c$