Final answer:
A bullet fired horizontally from a gun will hit the ground at the same time as a bullet dropped from the same height, as both are subject to the same gravitational acceleration, and projectile motion does not affect the time it takes to fall to the ground.
Step-by-step explanation:
The correct answer to the question of whether a bullet fired horizontally from a gun will hit the ground at the same time as a bullet dropped from the same height is C. Hit the ground at the same time as the dropped bullet. According to the principles of projectile motion, the horizontal velocity of the bullet does not affect the time it takes to fall to the ground. Both the bullet fired horizontally and the one dropped directly will be subject to the same gravitational acceleration, assuming that air resistance is negligible. Therefore, they will hit the ground simultaneously.
This is illustrated by Galileo's famous experiment, which concluded that two objects of different masses and shapes fall at the same rate in the absence of air resistance. Furthermore, the muzzle velocity only affects how far the bullet will travel horizontally before hitting the ground, not how quickly it will hit the ground in the vertical sense.