[Grooming Dispute] Marcus Has a Successful Dog Grooming Business Called

[Grooming Dispute] Marcus has a successful dog grooming business called "Bark & Bath." He registered the business name for trademark protection. Jonah noticed how well Marcus was doing and opened his own business called "Bark & Bath II." Marcus is unhappy about Jonah's use of the name. He is also unhappy because Jonah is copying Marcus's practice of tying a bright orange bandana around each dog's neck immediately after grooming. Marcus sues Jonah for trademark infringement based upon the name and the use of the orange bandana. Jonah replies that one reason Marcus should not prevail is that he is involved primarily in the sale of dog grooming products while Marcus is involved in the grooming of dogs. Jonah claims that his use of the orange bandana is very rare because he does very little grooming. Jonah also defends on the basis that actual confusion among consumers does not exist. Marcus insists that he should prevail and notes that he is considering expanding into the product sales area.
-Regarding Marcus' claim that the name Jonah chose violates his trademark protection, which statement is accurate?

A) In order to constitute trademark violation, Jonah's store would need to have been called the exact same thing as Marcus' store without the "II."
B) A key inquiry is whether a similarity exists which is likely to cause confusion, applied from the perspective of the defendant.
C) The key inquiry is whether a similarity exists which is likely to cause confusion from the perspective of the plaintiff, meaning that the plaintiff has acted willfully.
D) The key inquiry is whether a similarity exists which is likely to cause confusion, applied from the perspective of prospective purchasers.
E) A key inquiry is whether the defendant sold goods or services to customers that likely would have been customers of the plaintiff were the defendant not in business.