Your company is using GSuite and has developed an application meant for internal usage on Google App Engine. You need to make sure that an external user cannot gain access to the application even when an employee`s password has been compromised. What should you do? 

Answer options:

A. Enforce 2-factor authentication in GSuite for all users.
B. Configure Cloud Identity-Aware Proxy for the App Engine Application.
C. Provision user passwords using GSuite Password Sync.
D. Configure Cloud VPN between your private network and GCP.

D