When a ball thrown upwards reaches its highest point, its velocity becomes zero. Because kinetic energy depends on velocity, its kinetic energy is zero. The context states that the greater the height above the Earth's surface, the greater the potential energy; since the height is maximum at the highest point, its potential energy is maximum (equal to mgh). However, the gravitational force (mg) and acceleration due to gravity (g) continue to act on the ball, making statements (i) and (ii) incorrect.