Answer:
John is using structural level systems thinking. He has identified a pattern in the data and is looking into the problem to try and identify the cause behind it.
Step-by-step explanation:
Structural level systems thinking involves looking at data and recognizing patterns in it. In this case, John looked at customer complaints over a two-month period and identified that there were seven complaints on Sundays, two complaints on Wednesdays, and one complaint on a Friday. He then noticed that all of the Sunday complaints took place in the afternoon, and that they all revolved around a housekeeping issue. Thus, he concluded that there must be some underlying problem causing these complaints and he decided to look into it further.