Answer: The correct answer is 1.95 M
Step-by-step explanation:
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of unknown acid which is HCl.
are the n-factor, molarity and volume of base which is

We are given:

Putting values in above equation, we get:

Hence, the concentration of unknown HCl solution comes out to be 1.95 M.