Which of the following take place in both PCT and DCT?

a) Reabsorption of ${\mathrm{HCO}}_3^{-}$

b) Reabsorption of ${\mathrm{Na}}^{+}$

c) Selective secretion of ${\mathrm{H}}^{+}$

d) Conditional absorption of ${\mathrm{H}}_2\mathrm{O}$

The PCT and DCT are involved in the reabsorption of bicarbonate ions (HCO₃⁻) and sodium ions (Na⁺), as well as the secretion of hydrogen ions (H⁺). These processes are essential for regulating acid-base balance and electrolyte levels in the body.
Conditional absorption of H₂O takes place in DCT and collecting duct, under the influence of ADH.