When You Watch a Professional Football Game, You May See

When you watch a professional football game, you may see the Nike swoosh on the players' jerseys. When you see people on the street, you may see people wearing Nike T-shirts or Nike shoes. It seems, at times, most everybody sports that swoosh. You are likley to say: "Gosh, Nike must be a monopoly." But think twice. Is it? To define the market it's in, it would be most helpful if you had information concerning

A) its prices relative to those of other firms producing similar goods, such as Reebok
B) the shape of its demand curve
C) its cross elasticities of demand with other goods and its market share
D) whether or not brand loyalty exists
E) whether it advertises or not