In a simple DC electric motor, which component reverses the direction of current in the coil after every half rotation?

1. To keep the loop rotating in one direction, the current in it must reverse each half turn. 2. The chapter explains that after half a rotation the two halves X and Y of the split ring swap their contact with the brushes, reversing the current in the loop. 3. The option the carbon brushes are stationary contacts; they do not themselves swap the current, the split ring does. _Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 4 "Effects of Electric Current", p.65_