A Patient with Severe Vertigo Secondary to an Inner Ear

A patient with severe vertigo secondary to an inner ear infection suffers from a protracted bout of vomiting.She is most at risk for systemic symptoms related to reduced plasma concentration of which of the following electrolytes?

A) HCO₃^-
B) Cl^-
C) Na⁺
D) H⁺
E) K⁺