Final answer:
Young Javier is most likely to run to his mother and proudly show her the book he read at school today.
Step-by-step explanation:
Based on the information provided, young Javier, after getting off his school bus, is most likely to run to his mother and proudly show her the book he read at school today (option A).
This inference can be made because the passage describes Javier as eager to share his day with his parents, and running to his mother and proudly showing her a book he read at school would be a form of excitement and sharing.