Barb Is Buying a Book Online

Barb is buying a book online.They are asking her to give them a large amount of personal information before she is able to buy the book.The book site describes what will happen with the information and they also provide a way for Barb to ask them to collect no more data on her.The principle best described by this scenario is

A) liability
B) due process
C) safe harbor
D) informed consent