I'm pretty sure it's sunscreen
The answer is:
d) the sound originates from a vibration.
The explanation:
The sound waves are generated by a sound source, such as the vibrating diaphragm of a stereo speaker. The sound source creates vibrations in the surrounding medium. As the source continues to vibrate the medium, the vibrations propagate away from the source at the speed of sound, thus forming the sound wave.
The sun is the primary source of light. Other artificial sources are light bulb, torch light and some others. Thats all i can think of.
