In a bottle we have NaCl 500 ml, and to obtain we should add what volume of H2O to get percent dilution 3 (H2O): 1 - NaCl

In a bottle we have NaCl 500 ml, and to obtain we should add what volume of H2O to get percent dilution 3 (H2O): 1 (NaCl)?
a- 1500 ml.***
b- 2500 ml.
c- 3000 ml.