If one root of the eqn., $x^2+px+12=0$ is 4, while the eqn., $x^2+px+q=0$ has equal roots, then the value of $q$=?

Question

(A) $\large\frac{49}{4}$

(B) $\large\frac{4}{49}$

(C) $4$

(D) cannot be determined.