The correct option is A 331.7x103g/m3
Absoulute humidity is the actual amount of the water vapour in grams present in one cubic meter volume of air. It is expressed in in unit grams per meter cube (g/ m3).
So, the volume of air present in the cylinder = πr2h= (3.14*4*4*30) =1507.3cm3 i.e.,1.507x10−3m3
Amount of water vapour = 500g
Hence, the absoulute humdity is (500g)/(1.507x10−3m3)=337.1x103g/m3