Two beams of Light of intensity $\mathrm{I}_{1}$ and $\mathrm{I}_{2}$ interfere to give an interference pattern. If the ratio of maximum intensity to that of minimum intensity is $(16 / 4)$ then $\left(\mathrm{I}_{1} / \mathrm{I}_{2}\right)=$
(A) $1: 9$
(B) $1: 4$
(C) $4: 1$
(D) $9: 1$