In the axoneme, sidearms

a. in the axoneme, sidearms generate force to slide microtubules past one another.
b. link adjacent doublet microtubules to limit sliding.
c. are complete 13 protofilament microtubules.
d. project toward the central pair from each outer doublet.
e. are 10 protofilament incomplete microtubules attached to 13 protofilament microtubules.

A

Explanation: The sidearms consist of axonemal dynein. The dynein arms, for example, are motor complexes that produce the force needed for bending. Each dynein arm is anchored to a doublet microtubule by walking along an adjacent microtubule, the dynein motors can cause the microtubules to slide against each other. When this is carried out in a synchronized fashion, with the microtubules on one side of the axoneme being pulled 'down' and those on the other side pulled 'up,' the axoneme as a whole can bend back and forth. The human sperm is a well known example

c) should be the answer.