Question: Ms. Bristol measured the mass of a closed beaker containing several ice cubes. The mass was 100 g. An hour later, after the ice cubes had melted, Ms. Bristol measured the mass of the beaker again. What was the mass of the beaker of water the second time?

  Options: 
 A. 50 g
 B. 75 g
 C. 100 g
 D. 125 g
Answer: C