Select the Correct Statement About the Summation of Simple Twitches

Select the correct statement about the summation of simple twitches.

A) They can occur because of the long duration of the action potential in a muscle fiber.
B) They reduce the tension in a muscle.
C) They result from the slow stimulation of a muscle fiber.
D) The effect is unrelated to the refractory periods of action potentials.
E) The twitches resulting from separate action potentials add together.