Which of the following IT elements allows developers to leverage existing code to integrate with other software systems?

SaaS (Software as a Service) is a software distribution model where applications are hosted by a vendor and made available to customers over the internet, not an element for code integration.

An Application Programming Interface (API) is a set of defined rules that allow different software applications to communicate and interact with each other. Developers can use APIs to leverage existing code or functionality from one system and integrate it into another, enabling seamless data exchange and feature sharing.

Databases store and manage data, and while they are part of many software systems, they are not the primary mechanism for integrating existing code functionality between different applications.

End user applications are complete software programs designed for direct use by end-users, not for developers to integrate code with other systems.