The concentration of a stock solution is 2.000 M. What volume of stock solution is needed to prepare 20.0 mL of a 0.100 M diluted solution?

a) 10.0 mL
b) 2.50 mL
c) 0.025 mL
d) 10 mL
e) 1.0 mL
f) 0.010 mL