What should you do?

Your company develops an application named App1 that is deployed in production.
As part of an application update, a new service is being added to App1. The new service requires access to an application named App2 that is currently in development.
You need to ensure that you can deploy the update to App1 before App2 becomes available. You must be able to enable the service in App1 once App2 is deployed.
What should you do?
A. Implement a feature flag.
B. Create a fork in the build.
C. Create a branch in the build.
D. Implement a branch policy.