The Henry's Law Constant for O₂ in Water at 25 $\circ$

Multiple Choice

The Henry's law constant for O₂ in water at 25 ^$\circ$ C is 1.3 $\times$ 10^-3 mol/kg.bar.What partial pressure of O₂ (in atm) is necessary to achieve an equilibrium concentration of 2.9 $\times$ 10^-3 mol/kg O₂? (1 atm = 0.9869 bar)

A) 0.44 atm
B) 0.45 atm
C) 2.1 atm
D) 2.3 atm
E) 3.8 atm