Answer: Human perception of light and sound
Step-by-step explanation:
According to the given question, if we compare the physics and the psycho-physics then the psycho-physics is basically studying about the different types of human perceptions of the sound and the light.
On the other hand, the physicists is study about the various types of sound and the light properties.
The psychophysics is basically responsible for studying about the relationship between various types of physical characteristics about the frequency pf the sounds, sensations and the light based on the human perception.
Therefore, Human perception of light and sound is the correct answer.