Eliza places an 18-gram piece of an unknown substance into a graduated cylinder that is filled with 5 mL of water, and the water rises from the 5 mL line to the 8 mL line. What is the density of the unknown substance in g/mL?
A) 3.6 g/mL
B) 8 g/mL
C) 0.167 g/mL
D) 6 g/mL
Plz helpp