Which belongs in the summary because it is another important event
caused by the main problem?

problem: the miller needs a job and worries about

quick i need this

The miller continues to treat his son very poorly

Step-by-step explanation:

The main problem is that the miller needs a job and worries about people's opinion of him.

So, the miller is worried as he does not have a job and because of that, his behavior to his son is continuously very poor.

Hence, there is a separate event that the miller continues to treat his son very poorly and this is caused by the main event i.e. the miller does not have a job and he needs a job and he cares about people's opinion of him. (Answer)

it would be:

c.parallelogram.