A 1.50 M NaCl stock solution is used to prepare two successive dilutions. First, 20.0 mL of the stock is transferred to a 250 mL volumetric flask and diluted to the mark to make solution A. Next, 10.0 mL of solution A is transferred to a 100 mL volumetric flask and diluted to the mark, producing solution B. What is the molarity of NaCl in solution B?
a) 0.024M
b) 0.120M
c) 0.012M
d) 0.060M