Which of the following has the greatest density?

A. An object with a mass of 30 grams and volume 3 cm^3
B. An object with a mass of 20 grams and a volume 5 cm^3
C. An object with a mass of 50 grams and a volume of 10 cm^3
D. An object with a mass of 40 grams and a volume of 5 cm^3