Answer:
b.The power dissipated is reduced by a factor of 2.
Step-by-step explanation:
The power dissipated in the circuit is given by

where
V is the voltage
R is the resistance
In this problem:
- The voltage V is kept constant
- The resistance is doubled, so R' = 2R
Therefore, the new power dissipated is

so, the power dissipated is reduced by a factor of 2.