The correct answer is C) The "2S" contactor connects the autotransformer to the line during the starting/acceleration period. This is because the purpose of the "2S" contactor is to connect the autotransformer to the line during the starting and acceleration period of an electric motor. The autotransformer is used to reduce the voltage applied to the motor during start-up, which helps limit the high inrush current and allows the motor to smoothly accelerate to its full operating speed. The other answer choices are incorrect because they do not accurately describe the function of the "2S" contactor. Option A is incorrect as the "1S" contactor, not the "2S", would be responsible for the delta configuration during start-up. Option B is incorrect as the "2S" contactor connects the autotransformer to the line, not the wye configuration. Option D is incorrect as the "2S" contactor is used during the starting/acceleration period, not the run period.