Final answer:
The most likely consequence of a single late mortgage payment for Jim and Jennifer, who have otherwise excellent credit, would be a slight decrease in their credit score. Repeated late payments could have more severe consequences.
Step-by-step explanation:
The most probable consequence of Jim and Jennifer's late payment on their mortgage, assuming all other payments have been on time, is Option 1: A slight decrease in their credit score. Late payments can impact a borrower's creditworthiness, as they may appear less likely to repay a loan on time. However, if subsequent payments are made regularly, the effect on the credit score may be minor. A late payment will not typically result in a decrease in the borrower's interest rate on the loan or a decrease in their credit limit unless it becomes a repeated behavior.