What is a common use of bases?
as a component of vinegar
as a component of car batteries
to make foods tart
to reduce indigestion

Option (d) is the correct answer.

Explanation:

When we feel pain in our stomach due to the formation of excess acid then it can only be neutralized by a base.

So, the most common use of bases is to reduce indigestion.

For example, antacids neutralize the effect of excess acid formed into the stomach, it also helps in relieving heart burn, stomach upset etc.

the answer to this question is 3.