Which file is primarily used to manage the project’s dependencies in a Node.js project?

In a Node.js project, the package.json file is primarily used to manage project dependencies. This file contains metadata about the project and a list of dependencies required for the project to run. It specifies the name, version, and other essential information about the project, along with the dependencies and their versions. The other options (app.js, index.html, and server.js) are commonly used file names in Node.js projects but are not used for managing dependencies.