I believe the sentence is too vague.
Answer:
The effect of Audrey's parents suing the city to integrate public parks was C. The city closed all of its parks.
Explanation:
The sentence directly after where it states that Audrey's parents sued the city states that the city closed all of its parks. Therefore, the cause is Audrey's parents suing the city, and the effect is the city closed all of its parks.
If a person for example is in the situation of comiting suicide, they can be saved by someone who is witnessing the person. The person can confront the person comitting suicide by talking to them gently about why they are doing it or they can also call kids help phone.
When the movie ends, what the oak tree does at the theater is that it leaves.
This is a pun supposed to have a humorous effect on the listener or the reader - usually, when a movie ends, people leave the theater. However, since this is a tree, and it's got leaves, you can understand the correlation between the two words.