A Magnesium Sulfate Heptahydrate Solution, Which Is 18

A magnesium sulfate heptahydrate solution, which is 18.00% by weight in the anhydrous compound, has a density at 20°C of 1.20 g/mL. What is the molarity of the anhydrous compound in the solution? (Atomic weights: H = 1.0, O = 16.0, S = 32.1, Mg = 24.3)

A) 5.54 M
B) 1.79 M
C) 1.82 M
D) 1.25 M
E) 1.49 M