Which if the following actions is NOT a cause for suspension or revocation of a New Jersey Real Estate license?

a) failing to provide a cient with a copy of the signed exclusive listing contract

b) delivering a CIS to a seller after having made a listing presentation

c) payment of a referral fee by a licensed New Jersey broker to another broker licensed in another state

d) collecting a commission as a broker from both parties to a transaction while representing both parties as their agent