Answer: d. a slower response to a stimulus and sustained without fatigue.
Explanation:
The activity of the enzyme ATPase is slower in the smooth muscles as compared to the skeletal muscles as a result the production of ATP is also slow this can directly affect the response giving ability of the smooth muscles to the stimulus so there is an delay in the response given by the smooth muscles. The smooth muscle cells are involuntary. They use very little amount of ATP does during energy requirements they sustain without fatigue.
