Which statement about JavaScript modules is false?

The statement regarding modules executing multiple times is false because, in JavaScript, modules are designed to be singleton instances. Once a module is loaded, it is cached, and any subsequent requests for that module will receive the cached instance rather than re-executing the module code. This is beneficial as it ensures that the module maintains a single instance, thus preserving state and reducing overhead.

In the context of the other options, modules indeed execute in strict mode by default, meaning stricter parsing and error handling. Furthermore, upon their first loading, modules are executed once and then cached for any further imports. The import statements, like variable declarations, are also hoisted, meaning they can be referenced before they appear in the code context, simplifying code organization and clarity. Understanding these characteristics of JavaScript modules is essential for effective module design and usage.