A Buyer and Seller Have Been Doing Business for Months

A buyer and seller have been doing business for months without a formal contract. Every Monday, the seller delivers supplies to the buyer's business. Every Thursday, the buyer pays the invoice by mail. Is there a contract between the parties?

A) in jurisdictions where the offer-acceptance rule is rigidly applied there is a contract under both the UCC and the common law of contracts
B) in jurisdictions where the offer-acceptance rule is rigidly applied there is no contract under either the UCC or the common law of contracts
C) under the UCC, a contract has been formed by the conduct of the parties
D) under the UCC, there is no contract formed because the delivery of supplies is a service, not a good
E) under the UCC there is no contract, but there is a quasi-contract under the common law