Action and use of circuit components — practice question

The diagram illustrates a simple circuit. What occurs when the resistance of the variable resistor is increased?

• AThe lamps are dimmer and the motor rotates more quickly.
• BThe lamps are dimmer and the motor rotates more slowly.
• CThe lamps have the same brightness and the motor rotates more quickly.
• DThe lamps have the same brightness and the motor rotates more slowly.