Question

An acid-base titration is a neutralization reaction performed to determine: the concentration of an unknown acid based upon the concentration of a known base

the concentration of an unknown acid based upon the concentration of a known acid
the amount of salt that will be produced from the reaction of the acid and base the amount of water that will be produced from the reaction of the acid and base

Answer 1

A is your answer, "the concentration of an unknown acid based upon the concentration of a known base"