Answer:
C. selectively focus on certain stimuli
Explanation:
The reason that people do not become overwhelmed by their environments is that consciousness allows people the awareness to - selectively focus on certain stimuli.
Stimuli or stimulus is something that provokes activity in any organism. The stimulus can be internal or external.
Our sensory receptors and sensory organs are sensitive to external stimuli.
Our brain can work in such a way that it can control the order of stimulation. Its not necessary that all stimuli are experienced. The brain can focus on some certain stimulus according to its surrounding.