A projectile is launched from level ground and lands back on the same level; air resistance is negligible. Consider statements I to IV and select the option that names every correct statement and no incorrect one.

• I. The horizontal component of the projectile's velocity stays constant.
• II. The time of flight depends only on the vertical component of the launch velocity.
• III. The speed of the projectile at the highest point is zero.
• IV. For a given launch speed, the range is maximum at a launch angle of 45°.