Please help! I don't get this one!!

Match the term with its description.

Match Terms with Definitions

Term
Acid
Base
pH
Litmus pape

Definition
A) A value from 0 to 14 that is used to specify how acidic or basic a compound is when it is dissolved in water
B) Used to measure the pH of substances by determining their hydrogen ion concentration
C) A compound that increases hydroxide ions (OH−) when it is dissolved in a solution
D) A compound that increases hydrogen ions (H+) when it is dissolved in a solution