Which of These Companies Is Demonstrating a First-Mover Advantage

Which of these companies is demonstrating a first-mover advantage?

A) Tide-All Inc. has more than 50 percent market share in the telecom industry, because no other company has invested in this industry before Tide-All Inc.
B) The first 50 people who respond to the tweet sent out by Hal's Hamburgers receive a $5 coupon they can use on their next order.
C) The level of satisfaction Simon experienced when dining at the Tasty Cafe was highest the first time but reduced each time he dined there.
D) Innovative Creations Inc. was the first to exit the declining pager phone manufacturing industry and as a result, it avoided losing a lot of money.
E) Jenna has been asked to review the mascara she bought from AllWell Beauty. Her feedback will help the company improve the product.