Which of the following is an example of a cloud on a title?

A cloud on a title refers to any claim, lien, or encumbrance that may invalidate or impair the title to property or make it questionable. The presence of a cloud indicates that there may be something that could potentially challenge the ownership of the property or create uncertainty in the property's legal status.

In this context, a mechanic's lien is a perfect example of a cloud on a title. It arises when a contractor or subcontractor has not been paid for work performed on the property and files a claim against it. This lien serves as a notice to prospective buyers or lenders that there is a debt tied to the property, which can affect the owner's ability to sell or refinance it until the lien is resolved.

On the other hand, a property deed is an official document that represents ownership of the property; it does not in itself create any issue regarding the title. A mortgage agreement is a loan secured by the property, which is a standard encumbrance but is not necessarily a cloud unless there are problems with it being paid. Lastly, a service contract, which outlines the terms for services to be performed on the property, does not typically affect the title's validity or create any claims against it.