A locksmith company must provide which type of service?

The focus for a locksmith company is primarily on installing, servicing, and repairing locks and mechanical devices. This includes a wide range of responsibilities, such as creating keys, unlocking doors, and ensuring that locking mechanisms function properly. The core expertise of locksmithing lies in working with various locking systems, which is why this option accurately describes the essential services they are required to provide.

Transporting money securely is not a typical service associated with a locksmith company; this task would usually be handled by armored car services or security firms specializing in cash transport. Offering alarm system monitoring relates more to security companies that manage alarm systems for clients. Providing security training falls under the purview of firms that educate on security practices rather than locksmith companies focused on physical security hardware.

Thus, the correct answer captures the fundamental and specialized duties of a locksmith company.