How can phase to phase relationship impact the project completion?

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Roy is Sales portfolio manager. In line with organizations strategy Roy approves a plan for new global sales CRM. The organization is spread across different geographies in 22 countries. While most of the features are common there is also a lot of uniqueness in operations of each country. After debating on if CRM implementation should be a program or project, Roy agrees to implement it as a project. He on board Caroline, a senior project manager with 15 years of experience. Soon Caroline realizes that the project has to be multi-phased.

She had multiple brainstorming sessions with Sales leaders from all different countries, to decide which phase to phase relationship has to be chosen. But she could not get common agreement on the decision.
Some of the Sales leads are inclined to the sequential relationship while others are in favor of overlapping relationship. CFO, the sponsor, is inclined to go with the overlapping relationship. The project has to start soon and complete within one month. It is a difficult situation for Caroline as she knows that unless a decision with regards to phase to phase relationship is made she cannot complete project plan.

Phase to Phase relationship decision will create the biggest challenge for which subsidiary plan in Project management plan for Caroline?

A. Phase to phase relation will have maximum impact on Human Resource Management plan as the choice may impact the resource needs, and it will also influence how the team will be acquired in each phase of the project.

B. Phase to phase relation will have maximum impact on risk management plan as the wrong decision may increase project risk, and it will impact on how the risks are qualified and quantified in each phase of the project.

C. Phase to phase relation will have maximum impact Schedule Management plan. The relationship will influence the scheduling tool and the methodology in developing Schedule network diagram. It will also influence the schedule compression technique

D. Phase to phase relation will have maximum impact Requirements Management plan as the decision will dictate on how the requirements for each phase will be completed or fully defined before the next phase begins.

Which option is correct?