Which solution is the most concentrated?

The correct answer is letter C. 6 moles of solute dissolved in 4 liters of solution with 1.5 M.

Here are the choices.

A. 1 mole of solute dissolved in 1 liter of solution (1 M)
B. 2 moles of solute dissolved in 3 liters of solution (0.67 M)
C. 6 moles of solute dissolved in 4 liters of solution (1.5 M)
D. 4 moles of solute dissolved in 8 liters of solution (0.5 M)