Exam MS-721 topic 1 question 17 discussion

Your company has offices in Paris and London.
You are migrating from an on-premises PBX telephony solution to a Microsoft Teams Phone deployment that uses Direct Routing. You plan to use the existing telephony carrier. The new solution will provide telephony services to users in Both offices.
You need to recommend a solution that is the most resistant to possible failures. The solution must ensure that calls are routed through each user's respective office.
Which two actions should you include in the recommendation? Each correct answer presents part of the solution.
NOTE: Each correct selection is worth one point.