Answer:
Magnesium hydroxide
Step-by-step explanation:
Toothpaste as such is a mild base. This helps to neutralize the acid produced in the mouth as a result of the action of certain bacteria that help in breaking down food.
Sorbitol is a sugar alcohol and acidic in nature
Carrageenan is a linear polysaccharide and also acidic
Sodium lauryl sulfate is a surfactant and mildly acidic
However, magnesium hydroxide (Mg(OH)2) is a base which is used in toothpastes.