Put these in order for the muscle contraction process

ca^2+pumps restore cato sr → relaxation!
action potential travels down the axon in response to nerve
stimulus.
(myosin binds to actin
action potential causes caat release from sr
myosin pulls actin chain along and sarcomere shortens
contraction!
action potential travels down the t tubule and into
sarcoplasmic reticulum (sr)
ca^2+binds to troponin. troponin moves tropomyosin
uncovering myosin binding site on actin

The diagram below shows the layers of a rock having a trilobite: a rock column labeled rock is shown. the column has three layers. the bottommost layer of the rock has one shaded rhomboid shape, the middle layer has a rhombus with a diagonal along with two identical organisms marked as, trilobite, in the key, the top layer has two semicircles. a key is shown on the right side of the diagram. the shaded rhombus is marked as a, the rhombus with the diagonal is marked as b, the semicircle is marked as c which statement about the rock fossils is true?