Natural rubber is obtained from latex, which is a colloidal dispersion of rubber in water. Which of the following is used as a coagulant in latex ?

Natural rubber is obtained from latex, which is a colloidal dispersion of rubber in water. Which of the following is used as a coagulant in latex ?

A. Ammonium alum
B. Potassium alum
C. Both A. & B.
D. Neither A. nor B.