$\mathrm{t}_{1}$ and $\mathrm{t}_{2}$ are two values of time of a projectile at the same height $t \mathrm{t}_{1}+\mathrm{t}_{2}=$
(A) Time to reach maximum height
(B) flight time for the projectile
(C) $(3 / 4)$ time of the flight time.
(D) $(3 / 2)$ time of the flight time.