A body is projected vertically upwards. If $t_1$ and $t_2$ be the times at which it is at height h above the point of projection while ascending and descending respectively. then h is,

Question

$\begin{array}{1 1}(A)\;\frac{1}{2}g t_1t_2 \\(B)\;g t_1t_2\\(C)\;2g t_1t_2\\(D)\;4g t_1t_2 \end{array}$