Answer:
c. He will compare himself to people with a similar background to his own.
Step-by-step explanation:
According to the Social-comparison theory, we are constantly trying to have a more accurate image of ourselves. In order to do so, people make social comparisons.
When we want to see ourselves in a more accurate way, we compare ourselves to people who are in similar situations or have a similar background to our own (As opposed to comparing ourselves to people who are in a position of disadvantage compared to us and therefore, ending feeling better about ourselves).
In this example, Charles wants to see himself accurately, therefore, as we said before we will more likely compare himself to people who are in similar circumstances and therefore with a similar background to his own.