A 56-Year-Old Woman with Severe Muscle Weakness Is Hospitalized $\mathrm{K}^{+}$ Concentration $\mathrm{K}^{+}$

A 56-year-old woman with severe muscle weakness is hospitalized. The only abnormality in her laboratory values is an elevated serum $\mathrm{K}^{+}$ concentration. The elevated serum $\mathrm{K}^{+}$ causes muscle weakness because

A) the resting membrane potential is hyperpolarized
B) the $\mathrm{K}^{+}$ equilibrium potential is hyperpolarized
C) the $\mathrm{Na}^{+}$ equilibrium potential is hyperpolarized
D) $\mathrm{K}^{+}$ channels are closed by depolarization
E) $\mathrm{K}^{+}$ channels are opened by depolarization
F) $\mathrm{Na}^{+}$ channels are closed by depolarization
G) $\mathrm{Na}^{+}$ channels are opened by depolarization