Final answer:
A written mutual agreement is required to extend the loan objection deadline. Without it, the transaction may terminate if the buyer cannot meet the deadline.
Step-by-step explanation:
If the buyer cannot meet the loan objection deadline, the typical action that should be taken is a written mutual agreement to extend the deadline. Verbal agreements, while perhaps made in good faith, are not considered binding in such a context.
A certified letter might be used for formal notices but does not replace the need for a written extension of the deadline. Without a written agreement to extend or waive the objection deadline, if this deadline passes without the loan objection being resolved, the transaction can terminate according to the contract's terms.