Final answer:
XYZ Insurance would not be allowed immediately to increase Kate's policy premium if she recently completed a defensive driving course approved by the state, as it illustrates a lower risk profile and safe driving commitment.
Step-by-step explanation:
The scenario in which XYZ Insurance would NOT be allowed immediately to increase Kate's policy premium is Option 2: Kate recently completed a defensive driving course approved by the state. Completing an approved defensive driving course often indicates that a driver is invested in safe driving practices, potentially lowering their risk profile. Insurance companies regularly offer discounts or prevent premium increases for drivers who take such proactive steps to improve their driving skills, considering them lower risk compared to drivers who have not taken such courses.
In the other scenarios, such as being involved in an at-fault accident (Option 1), adding a new and inexperienced teenage driver to the policy (Option 3), or missing a payment (Option 4), the insurance company may have grounds to increase the premium because these actions can be associated with higher risk. However, if the missed payment is made within the grace period, it may not immediately affect the premium, but typically, repeated late payments or other risk-related changes to the policy could lead to increased premiums over time.