Which of the following is correct about the flatworm’s muscular system?
It contains three types of muscle tissue.
It consists of two layers of muscle.
Its muscles are attached to a center bone.
Its muscles are all involuntary.

Question

Which of the following is correct about the flatworm’s muscular system? 
       It contains three types of muscle tissue.
       It consists of two layers of muscle.
       Its muscles are attached to a center bone.
       Its muscles are all involuntary.

anonymous · Answer

The well-developed muscular system present in flatworms is comprised of a subcuticular musculature consisting of layers of circular, longitudinal, and diagonal muscles

So basically they just named three types of muscle so i'd go with A.