Answer:
The correct answer is "the analyte".
Step-by-step explanation:
Titration is a method of quantitative chemical analysis used to determine the unknown concentration of a reagent from a reagent with a known concentration.
A reagent called a "titrator" of known volume and concentration is used to react with an analyte solution of unknown concentration. The endpoint is the point at which the titration ends, and is determined by the use of an indicator, which is added to the analyte.
Have a nice day!