In the given case, Nick is exhibiting selective attention.
Answer: Option D
Explanation:
In psychology, the process of channelizing one’s attention or awareness to a particular stimuli or task and ignoring the other irrelevant or unnecessary stimuli surrounding the person is denoted as selective attention.
This process has helped human to work efficiently as insignificant details are ignored by the brain and only essential information is focused upon.In this situation, where nick is paying attention to his studies and is ignorant of the ringing of his cell phone shows that he is exhibiting selective attention.