Answer: a. is an acid
Explanation: An acid is substance which donates [tex]H^+[/tex] ions when dissolved in water. A base is a substance which gives [tex]OH^-[/tex] when dissolved in water.
pH is the measure of acidity or alkalinity of a solution. Acids have pH ranging from 1 to 6.9. Bases have pH ranging from 7.1 to 14. Neutral solutions have pH of 7.
The chemical formula for vinegar is [tex]CH_3COOH[/tex]
[tex]CH_3COOH\rightarrow CH_3COO^-+H^+[/tex]