Pulleys using twisted belts may move in opposing directions.
The design of pulleys prohibits the pairing of pulley and gear, and a simple reversal of belts will result in synchronized reversal of all pulleys. To violate this rule, a belt must be twisted.
B To violate this rule, pulley system belts must be reversed.
C To violate this rule, pulley systems may be used in conjunction with gears.
D This rule cannot be effectively violated.