A ball is attached to a string hanging from the ceiling, forming a pendulum. The mass of the string is negligible compared with the mass of the ball. At time t = 0 s, the pendulum is shifted from the vertical to an angle 0 = 00, and then let go starting from rest. The angle 00, is quite small, so that the approximation of 0 = 00 is excellent. Which of the comments below is most correct? 1) If the length of the pendulum is doubled, the period of oscillation doubles. 2) The period of oscillation is proportional to the square of the acceleration of the gravity. 3) Lengthiest statement is wrong. 4) The period of oscillation is proportional to the square of the mass attached to the string. 5) The period of oscillation is inversely proportional to the square of the mass attached to the string.