Answer:
used to help understand
Step-by-step explanation:
A reading organizer is defined as a graphic organizer which is properly organized in a structure such as columns and rows, flow chart and use of visual depictions for better understanding.
A reading organizer can often be used to help understand things more easily and accurately which can be bit confusing in a simple passage or paragraph. A reading organizer organizes things more precisely and helps to tackle complex texts.
Hence, the correct answer is "used to help understand".