The sun emits electromagnetic waves at many frequencies, but mostly in the infrared, visible, ultraviolet spectrums. what kind of energy is this?
a. nuclear
b. radiant
c. thermal
d. chemical

Radiant

Explanation:

The light emitted from the surface of the Sun reach on the earth in different frequency. All frequencies that are incident on the surface of earth passes same medium and follows the same path between sun and earth. It has been studied that there is a space between earth and sun where there is no medium it has complete vacuum. Thus, while travelling the path between sun and earth the beam of light pass through vacuum.

Hence, the only form of transfer of heat that do not depend on the medium is radiation. so, The energy is radiant energy.

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )