A 48-Year-Old Woman Is Referred to an Allergy and Rheumatology $70 \mathrm{U} / \mathrm{mL}$

A 48-year-old woman is referred to an allergy and rheumatology specialist with itching eyes, dryness of the mouth, difficulty swallowing, loss of the sense of taste, hoarseness, fatigue, and swollen parotid glands. She reports increasing joint pain over the past 2 years. She complains of frequent mouth sores. Laboratory tests show a positive antinuclear antibody (ANA) and rheumatoid factor (RF) levels of $70 \mathrm{U} / \mathrm{mL}$ (normal $<60 \mathrm{U} / \mathrm{mL}$ ) by the nephelometric method. A parotid gland biopsy shows inflammatory infiltrates in the interlobular connective tissue with damage to the acinar cells and striated ducts. In this case, resorption of which of the following will be most altered by destruction of those ducts?

A) $\mathrm{Na}^{+}$
B) $\mathrm{H}_{2} \mathrm{O}$
C) $\mathrm{HCO}_{3}^{-}$
D) $\mathrm{Cl}^{-}$
E) $\mathrm{Ca}^{2+}$