Please solve question no 29

We have, 
Molar concentration= partial pressure x henry constant
Hence, C = p xK_​h​ 
Or, n/V =p xK_​h​ 
Or, n =p xK_​h​  xV
'Putting the values we get, no. of moles of oxygen gas as:
$n=0.5atmx0.1Lx1.4x10-3mol/atmL=0.00007$
Thus, 1 mole of oxygen gass= 32 g
Hence, 35.7 mole of oxygen gas = 0.00007x 32=2.24 x10^-3 g = 2.24mg
Correct answer is d). 2.24 mg