A client of yours has asked you for advice because he is looking for a quick and convenient solution for adding functionalities to an Application.
Whenever a new customer is created in the Firebase database, he wants to perform a series of welcome activities and a series of follow-up actions, regardless of the specific function that recorded the new customer record.
Which of the following solutions will you suggest (choose 1)?
A. Compute Engine and Managed Instances
B. App Engine Flexible Environment
C. App Engine Standard Environment
D. Cloud Functions
E. Cloud Run (fully managed)