The answer to your question would be that the sentence that can be used to depict the voice of a young character is the following one: We ran the cars and jumped in because we hated school.
I believe that this is the correct answer because of the word choices selected by the speaker. The verbs used are simple verbs of momevent (ran) or phrasal verbs (jumped in). Consequently, the tone is very informal, as opposed to the other sentences which make use of formal word choices adding a lot of description to the passage (eager to jump in our parents' cars, empty parking lot, bursting with excitement, dreaded school, glad to finally be leaving school).
The diction of Steinbeck here in apparently describing the dustbowl conditions of the Dirty Thirties is speaking of "tenant men" or presumably men who were tenant farmers perhaps who were allowed to live on the land in return for working it and that they "scuffed" their way home indicates that the dust was so thick they had to scuff but also perhaps that since they could barely make a living under the poor agricultural conditions they did not walk confidently but scuffed.
Neiterkob’s daughter most likely tell the myth “The Beginnings of the Maasai” to explain the readers the origin of Maasai culture. Option C is correct.
Neiterkob’s daughter finds it necessary to tell the myth “The Beginnings of the Maasai” in order to explain the origin to the readers, so that they will have broader knowledge and will grasp a better notion about it and will not feel lost or confused while reading this story.