Which of the Following Best Describes How the Pareto Principle

Which of the following best describes how the Pareto principle relates to selling?

A) Successful salespeople should listen twice as much as they talk.
B) In any human activity, the biggest results usually arise from a small number of activities.
C) The mind is like a muscle; if it is unused, it deteriorates.
D) To persuade a prospect to purchase your product you must first persuade him to "buy" your service.
E) Listening is a better selling tool than talking.