What should the Scrum Master suggest?

At the System Demo, each team demonstrates their own work but the system is not integrated. They say they underestimated the integration effort, but they cannot integrate every Iteration and meet the planned scope.

What should the Scrum Master suggest?
A . Integrate the system during the IP Iteration
B. Stop the Train and go back to waterfall until integration can occur
C. Defer integration until the train is in the sustain and improve the section of the Implementation Roadmap
D. Discuss removing scope with product management to allow for continuous integratio

Answer: C

Explanation:

https://www.scaledagileframework.com/system-demo/