Help asap for 10pt plzzz

it's not c. i took the quiz and got it wrong. so my best guess is b.

have a great day, and hope this .

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.

answer axon terminal,synaptic cleft; and motor end plate;