I think (C):600
Explained: other sources say there is about 650 but if you count the muscles within a complex muscle then about 840
"Pacemaker" is the one choice among the following choices given in the question that is the treatment that can also regulate heart rhythmsthat has replaced drugs in some cases. The correct option among all the options that are given in the question is the first option or option "A". I hope it helps you.
Where are your answer choices ?
