Potentials Question 15 Unanswered Hypokalemia (low extracellular K+ concentration), if sustained, will cause A depolarization B hyperpolarization C maintenance of resting membrane potential D difficulty achieving action potentials E both B and D are true Potentials Question 14 Unanswered Absolute and relative refractory periods are important aspects of which of the following? A Action potentials B Resting potentials C Hyperpolarizing graded potentials D Graded potentials .