The answer is C I got it right so hope it helped ;)
Sorry if I'm wrong but I think that it is B.
Answer:
Both molarity and formality express concentration as moles of solute per liter of solution. Formality is a substance's total concentration in solution without regard to its specific chemical form. ... The formality of a solution is defined as the number of formula mass of any solute dissolved in 1 litre of solution.