Answer:
NaOH
Step-by-step explanation:
Since no acid-base reaction equations are provided for each substance, we will have to use logic to find the answer. We can immediately eliminate vinegar and lemon juice, which are both acids, as acidic substances generally taste sour. Next, we can apply the idea of most acids having a +H in their chemical formula while most bases have a -OH in their chemical formula. Because HCl has a +H in its formula, it is an acid, and since NaOH has a -OH in its formula, NaOH is a base.