Option 1 states that the motion of the pendulum repeats after time T only once, which means that the motion does not repeat itself after multiple time periods. However, this statement is not correct. The motion of the pendulum actually repeats itself after each time period T.

Option 2 states that T is the least time after which the motion of the pendulum repeats itself. This statement is true since the time period T is the minimum amount of time required for the pendulum to complete one full oscillation and return to its initial position.

Option 3 states that the motion of the pendulum repeats itself after nT, where n is a positive integer. This statement is also true as the pendulum will complete one full oscillation after each multiple of the time period T.

Option 4 states that T remains the same only for small angular displacements. This statement is true for small angular displacements, but as the amplitude of the pendulum`s swing increases, the time period T may change due to changes in the restoring force.

In conclusion, option 1 is the correct answer as it incorrectly suggests that the motion only repeats once after time T.