Answer:
D. The temperature at which all molecular motion is stopped.
Step-by-step explanation:
Absolute zero is the theoretical temperature at which all matter would have zero thermal energy and all molecular motion would stop. This temperature is equal to -273.15 degrees Celsius or -459.67 degrees Fahrenheit. It is the lowest possible temperature in the universe and cannot be reached in practice, as it is impossible to completely eliminate all thermal energy from matter.