To be effective as an offer $($that is$,$ if the other side says $$I accept,$$ the courts would recognize it as a valid and enforceable contract$),$ which of the following must ALWAYS be present?

Group of answer choices

A$.$ The offer must be communicated to the offeree IN WRITING

B$.$ The offer must manifest an intent to enter into a contract $($is the communication just probing and negotiating or is the offeror ready to say $$I do$?)$

C$.$ Although the courts in some cases will fill in missing contract terms if there is a basis for doing so $($e$.$g$.,$ prior dealings between the parties, custom and usage in the trade$),$ the offer must be sufficiently definite and certain that the courts could decide what the deal is if the offeree says, $$I accept.$$

D$.$ B and C only

E$.$ A$,$ B$,$ and C must all be present