Which of the following is a suitable application for surface-mounted contacts?

Surface-mounted contacts are versatile security devices used to detect unauthorized entry by serving as alarm triggers. They work effectively on various surfaces and are suitable for both residential and commercial applications. Choosing file cabinets, roll-up garage doors, and safes as applications for these contacts illustrates their adaptability; they can be placed on a variety of surfaces where traditional detection methods may not be feasible.

Surface-mounted contacts are favored for their ease of installation and ability to provide status monitoring, making them ideal for protecting access to important areas or valuable items across different environments. When applied to file cabinets, they help secure sensitive documents. In the case of roll-up garage doors, surface-mounted contacts ensure that any unauthorized opening triggers an alert. For safes, they provide an added layer of security to safeguard important contents.

The other options are limited in scope. Restricting the use of surface-mounted contacts to just residential doors does not leverage their versatility. Similarly, saying they are only for outdoor settings or solely for industrial equipment overlooks their broad applicability across various scenarios where security is needed.