Which description best describes the factual matrix examined by the courts when interpreting contractual terms?

Which description best describes the factual matrix examined by the courts when interpreting contractual terms? Select one: O a. the evidence of the party's subjective intention or negotiations leading up to the contract O b. the impression of a 'reasonable bystander' of the parties' intentions O c. the plain meaning of the words used in the contract document itself O d. the background facts known to the parties when the contract was concluded