The correct answer is: B.
-273o CAbsolute zero is the lowest temperature possible. It is the temperature at which all molecular motion ceases. At absolute zero, the particles of a substance have no kinetic energy.
Option A is incorrect because 0o C is the freezing point of water.
Option C is incorrect because -276o C is the temperature at which liquid nitrogen freezes.
Option D is incorrect because 25o C is the temperature at which water is at room temperature.
Option E is incorrect because absolute zero is a real temperature, and it is not equal to any of the other options.