Which molecular event at the neuromuscular junction contributes to activation of a muscle contractio

1.   Which molecular event at the neuromuscular junction contributes to activation of a muscle contraction
a.   voltage-gated k+ propagation of an action potential along presynaptic axon
b.   glycine inhibition of voltage gated K+ hyperpolarization on postsynaptic membranes
c.    acetylcholine gated Ca2+ channel activation on postsynaptic membrane
d.   acetylcholine mediated closure of postsynaptic cation channel

2.   which is not true of cancer-critical genes
a.   gain of function genes are genetically dominant
b.   oncogenes activate programmed cell death
c.   loss of function mutation of tumor suppressor genes abolish the inhibitory controls that normally hold cell numbers in check
d.   specific cancer critical are mutated in the majority of all cancers