[填句补文]As part of their study， the researchers used a special machine to take action photos of the students‘ brains. ________. This is the same part of the brain that becomes active when good readers read. This activated brain area appears to include a structure that helps people recognize familiar written words quickly.
A、Do you have difficulty reading in class?
B、The pictures showed an increase in activity in the back of the brain on the left side.
C、As part of the study， 37 struggling readers received special tutoring.
D、By the end of the school year， these children could read faster than before.