Would a low calcium diet influence the contraction of a muscle?

1) No since sodium is the ion that takes the message into the cell. Calcium is only
important for going into the neuron to cause the release of ACH.
2) No since sodium is the ion that takes the message into the cell. Calcium is not used in the process of muscle contraction.
3) Yes since calcium is needed to uncover the active site on actin so that the cross
bridges can form and start the sliding process.

(NEED HELP ASAP AND I APPRECIATE YOUR HELP)