You found your vendor's subcontractor to be much more professional and easy to work with and started directly contacting them for project updates and other concerns. You are informed by the vendor that, as per the contractual relationship, this is not an ideal situation since you are only supposed to contact the vendor and not the vendor's subcontractor. The legal contractual relationship that exists between a buyer and a seller after the contract is signed that the vendor is referring to is known as: a. Bilateral agreement. b. Obligation c. Privity d. Legally bonded relationship\