Which of the following is NOT a reason for a landlord to enter the property without permission?

The statement that a landlord may enter a property without permission in the context of collecting overdue rent is accurate, as this is generally not justified under landlord-tenant laws. Landlords typically need to provide prior notice to tenants and follow legal protocols when it comes to entering a rental unit for various reasons. Collecting overdue rent does not fall within the established emergency or maintenance circumstances that allow for entry without prior notice or tenant permission.

In contrast, emergency repairs are situations that often require immediate access without notice to address urgent issues that could pose a danger to tenants or property. Showing the property to prospective tenants usually requires notice, but it can happen without tenant permission if the terms of the lease allow for periodic showings, provided sufficient notice is given. Regular maintenance checks are also justified grounds for entry, as they are part of the landlord's responsibility to ensure the property is well-maintained.

Overall, the collection of overdue rent does not meet the necessary thresholds that allow a landlord to bypass permission, making it the choice that is not a valid reason for entry without tenant consent.