A ball $B_1$ is projected from A at a velocity u making an angle $30 ^{\circ}$with the horizontal. Another ball $B_2$ is simultaneously projected from C verically up and with velocity v.Both collide each other at their maximum heights. What is ratio $\large\frac{u}{v}$

Question

$a)\;4 \\b)\;2 \\c)\;1 \\ d)\;0.5$