Speeding up Slowing down Standing still Holding at a constant non-zero velocity

speeding up is the answer

Explanation:

from the graph it can be seen that as the time (horizontal axis) increases the speed of vehicle (vertical axis) increases

A. Having long wavelengths.

Explanation:

Radio waves are long wavelengths electromagnetic waves which are used for communication purpose. These are used below ionosphere. Radio waves are preferred because they have long wavelengths and thus can traverse long distance without getting attenuated.

These have low frequency and thus low energy and are not harmful. The radio waves travel with the speed of light like all other EM waves.