A solution containing 27.40 mg of an unknown protein per 30.0 ml of solution was found to have an osmotic pressure of 3.50 torr at 18 °C. What is the molar mass of the protein?
a) 20,000 g/mol
b) 50,000 g/mol
c) 100,000 g/mol
d) 150,000 g/mol