Event Marketing LLC and Family Restaurant Inc

Event Marketing LLC and Family Restaurant Inc. engage in an instant-messaging conversation while discussing an existing contract. Event suggests a modification-an increase in fees. Family asks about an increase in service. Event replies, "No limits!" Family responds, "Great!" As a modification of the parties' contract, this chat is most likely

A) enforceable.
B) not enforceable because any indication of an agreement is "accidental."
C) not enforceable because it is an instant-messaging conversation.
D) not enforceable because the language is relatively "careless."