Hello. You did not inform Part A of the question, which makes it impossible for that question to be answered accurately. However, I will try to help you find the answer.
First, it is important that you read the full text, to understand the whole subject addressed by the author. After that, assuming you answered Part A, you should look in Part B for lines that support the Part A response. This line will be the one that provides a justification and proves the information covered in Part A, showing that it is true and real.