To build motivation for the character gives a backbone to the story and about the Arthur for example if the Arthur got the motivation from seeing a kid take a candy out of a store that motivation for that character would be a bad guy or a heel and or antagonist there for the motivation for a character is very important they reveal it so you can get a bit of a background on the character in more information on the story and the Arthur.
A.
Example,
While John was lying on his bed, Jack was outside playing soccer.
Answer:
D. "Thomas spotted a chocolate donut in the glass case" sounds correct to me.