Answer:
B. Avril is dyslexic, which means she has trouble understanding what she reads.
Step-by-step explanation:
This statement provides details that elaborate on the main idea that the writer exposes, he admires his sister, because she has a learning disability and still she is the hardest-working student he knows, and if you add to that the fact that she has dyslexia it can give a more profound meaning to the fact that she is doing well in school.