Both chemical and mechanical digestion start in the mouth and continue in the stomach.

A. It increases both Na+ and K+ secretion: Aldosterone increases sodium (Na+) reabsorption and potassium (K+) secretion, but it does not increase the secretion of both ions.

B. It causes the urine to be more diluted. Aldosterone causes the urine to be more concentrated by increasing sodium reabsorption and potassium secretion.

C. It reduces Na+ reabsorption and K+ secretion. Aldosterone actually increases sodium reabsorption and potassium secretion, not reduces them.

D. It increases Na+ reabsorption and K+ secretion. Aldosterone promotes sodium reabsorption in the kidneys and increases potassium secretion, leading to more concentrated urine.

A. ADH (antidiuretic hormone) promotes water retention by increasing water reabsorption in the kidneys. Estrogen does not mimic the action of ADH.

B. Natriuretic peptide promote sodium excretion, which leads to water loss, not retention. Estrogen does not mimic this action.

C. Oxytocin is primarily involved in labor and lactation, not water retention. Estrogen does not mimic oxytocin's effects.

D. Aldosterone promotes sodium and water retention by increasing sodium reabsorption in the kidneys. Estrogen can mimic the action of aldosterone, leading to water retention during certain phases of the menstrual cycle.