Which of the following is true about "tying" arrangements?
A) Tying arrangements are always illegal.
B) Tying arrangements are always legal.
C) Tying arrangements are legal for companies without monopoly power, and illegal for companies with monopoly power.
D) Tying arrangements are illegal, unless there is a justifiable reason for the seller to have the tying arrangement.
E) Tying arrangements are legal, so long as the purchaser is not harmed.