The vapour pressure of water at 293 K is 17.536 mm Hg. Calculate the vapour pressure of an aqueous solution when 20 g of glucose (molar mass = 180 g mol-1) is dissolved in 500 g of water. 
a) 17.036 mm Hg 
b) 17.136 mm Hg 
c) 17.236 mm Hg 
d) 17.336 mm Hg