What is the chemical benefit of basic toothpaste for teeth?

Correct answer: It neutralises acids in the mouth

The governing concept is acid–base neutralisation. Bacteria in the mouth can convert food sugars into acids, which lower pH and attack enamel. A mildly basic toothpaste reacts with or neutralises some of these acids, reducing their harmful effect and helping the mouth return toward a safer pH. Therefore option A is correct. It should not dissolve enamel, force pH to zero, or increase acidity.