A:
Calcium Oxide And Aragenite
B:
Calcium Carbonate And Magnesium Carbonate
C:
Amonium Chloride And Conchiolin
D:
Amonium Sulphate And Sodium Carbonate
Explanation
Pearls are composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers. Therefore, option B is correct.