Answer : The correct option is, (B) fresh water
Explanation :
When adding a non-volatile solute to the solvent the freezing point decreases. The vapor pressure is decreases. So, the solvent freezes at low temperature.
Th amount of freezing point depends on the amount of solute dissolved not on the type of solute.
From the given options, the fresh water freezes faster at the same temperature as compared to the salt water and a mixture of fresh water and salt water because as the amount of solute increases the freezing point decrease. So, the fresh water freezes faster.
Hence, the fresh water freeze faster at the same temperature.