I think the first one is the enwrapped one
Answer:
Cause and effect
Explanation:
The excerpt structure clearly shows cause and effect relationship as the sentence follows a pattern showing the reason or cause of a certain phenomen and the its effect. With the author highlighting the reason they had to ride segregated buses as being their inability to afford a car. Chronological lists events in order of occurrence. While problem and solution highlights an issue and it is followed up by the cure or remedy.
The answer is B!! Cool excerpt by the way.