Magnesium and Aluminium are added in Antacid because_____________?

Magnesium and Aluminium are added in Antacid because_____________?

A. Mg Causes constipation, Al causes diarrhoea
B. Mg Causes Diarrhoea, Al Causes Constipation
C. Mg act as buffering agent and Al antagonize its action
D. Both increase gastric motility