An organization wants its users to validate a series of new features (Digital Leader)

Correct answer: C) To run different versions of the app for different users.
Here's why:

A. Because their app is containerized and enabled by microservices: While App Engine does support containerized applications and can work well with microservices architectures, this reason doesn't directly address the need to validate new features for their app.

B. Because the updated app will only include new features: App Engine can deploy new versions of an app, but this reason doesn't specifically highlight why App Engine would be advantageous for feature validation.

C. To run different versions of the app for different users: This is a significant advantage of App Engine. It allows you to deploy multiple versions of your application simultaneously and direct specific users or user groups to each version. This capability is particularly useful for A/B testing and feature validation.

D. To run different versions of the app for the same user: While App Engine can technically support this scenario, it's not the most common or compelling reason to use it for feature validation. The ability to run different versions for different users (option C) is typically more relevant and beneficial for testing purposes.