[单选题]

We drop a piece of metal into a jar full of water, the metal will float if it weighs less than______.
A． an equal amount of silver
B． an equal amount of gold
C． all the water in the jar now
D． the water that leaves the jar

We drop a piece of metal into a jar full of water, the metal will float if it weighs less than______.A． an equal amount of silverB． an equal amount of goldC． all the water in the jar nowD． the water that leaves the jar