Answer:
The answer to your question is letter B. Phosphoric acid
Step-by-step explanation:
A. water is not the right answer because it has a density of 1 g/ml and water is a liquid not a solid.
B. phosphoric acid is the right answer because phosphoric acid is a solid and all solids have a density higher than water (1 g/ml)
C. sodium hydroxide could be the correct answer but it is not because the crystals of sodium hydroxide are more colorless than white.