Two bullets are fired simultaneously, horizontally and with different speeds from the same place. Which bullet will hit the ground first?

The correct option is C both will reach simultaneously
There is only horizontal component of velocity , no vertical component.

Since the bullets are fired horizontally from the same place, they have the same height.

The formula for Time is

$t=(\frac{2H}{g}{)}^{\frac{1}{2}}$

since the acceleration (g) is also same for both the bullets they will reach the ground at the same time.

Thus, the time taken to reach the ground is independent of the initial horizontal speed of the bullets. Hence, both the bullets fired simultaneously in the horizontal direction from the same height will reach the ground simultaneously.