A 0512 G Sample of an Unknown Nondissociating Solute Was Dissolved

Multiple Choice

A 0.512 g sample of an unknown nondissociating solute was dissolved in 25.0 g of camphor (K_f = 39.7 $\degree$ C/m) , decreasing the freezing point of camphor by 3.07 $\degree$ C.What is the molar mass of the solute?

A) 150 g/mol
B) 166 g/mol
C) 265 g/mol
D) 631 g/mol
E) 323 g/mol