indicate whether each statement is true or false regarding action potentials and the all-or-none principle.1. once the threshold is reached, an action potential will proceed without stopping. (click to select)2. the action potentials will be different in different parts of the cell. (click to select)3. if threshold is not reached, an action potential will occur, but it will be weaker. (click to select)4. if threshold is not reached, an action potential will not occur. (click to select)