Calculate the concentration (in molarity) of an NaOH solution if 25.0 mL of the solution is needed to neutralize 15.9 mL of a 0.247 M HCl solution. Be sure your answer has the correct number of significant digits.

a) 0.375 M
b) 0.412 M
c) 0.502 M
d) 0.576 M