Marketo Certified Expert Certification Practice Test 2025 - Free Marketo Practice Questions and Study Guide

The action that cannot be performed on an existing user is reusing the sandbox login. This is because sandbox logins are specifically designed for testing and are intended to be unique to each user set in the sandbox environment. If a sandbox login were to be reused, it could create conflicts, security issues, and difficulties in tracking user activity and changes in the test environment. Each user should have their own distinct sandbox account to ensure proper separation between testing and live environments, preserving the integrity of both.

Deleting a user, resetting the password, and changing the user role are actions that can be performed on existing users. Deleting a user removes their access and associated data; resetting the password allows the user to regain access if they've forgotten it; and changing the user role enables administrators to adjust permissions and responsibilities as needed.