Figure 9- 2 Muscle Contractions

Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
-To produce a contraction similar to the one in graph b) , the muscle

A) must be stimulated to the point of fatigue.
B) gradually warms up.
C) must be stimulated again before it has relaxed from the previous stimulation.
D) is excited by a stimulus of increasing intensity.
E) is caused to produce isolated twitches.