Water Contains About 42 Mg of Oxygen Per Liter at 20

Multiple Choice

Water contains about 42 mg of oxygen per liter at 20 $\degree$ C and 1 atm.What is the Henry's law constant for oxygen dissolving in water?

A) 0.25 mol/L . atm
B) 1.3 * 10^-3 mol/L . atm
C) 1.9 * 10^-2 mol/L . atm
D) 3.7 * 10^-2 mol/L . atm
E) 0.010 mol/L . atm