In a simple pendulum, which is an example of simple harmonic motion, the following statements are correct:

1. The kinetic energy is maximum at the mean position.

Explanation: The kinetic energy of an object is directly proportional to the square of its velocity. In a simple harmonic motion, the velocity is maximum at the mean position. Hence, the kinetic energy is at its maximum at this point.

2. The potential energy is maximum at the mean position.

Explanation: The potential energy of an object is directly proportional to the square of its displacement from the equilibrium position. In a simple harmonic motion, the displacement is maximum at the mean position. Hence, the potential energy is at its maximum at this point.

3. Acceleration is maximum at the mean position.

Explanation: The acceleration of a simple pendulum is directly proportional to the displacement from the equilibrium position. In a simple harmonic motion, the displacement is maximum at the mean position. Hence, the acceleration is at its maximum at this point.

Therefore, option 1 is the correct answer.