What unit is used to measure surface temperature of the planets? a. kelvin c. degrees celsius b. degrees fahrenheit d. angstroms

The correct answer is option A. Kelvin.

Explanation:

Kelvin is the is unit of temperature measuring like Celsius and Fahrenheit. The planet's temperature is mostly measured in the kelvin unit of temperature however degree Celsius and degree Fahrenheit also use to measuring in many cases.  

Kelvin is an international unit of temperature which is equal to the -273 degree celsius and in planetary science mostly kelvin is used as the unit of measurement.

Thus, the correct answer is option - a. kelvin