A customer plans to consolidate several systems onto POWER7. Their immediate requirement is to have a single Power 770, and they will buy a second Power 770 at a later stage. They want to keep their existing three POWER5 570s and three POWER6 520s which are all managed by an HMC (7310-CR3). Which of these statements is true and would minimize the cost?（）
- AAll the machines can be connected to the existing HMC, as long as it is updated to code level 7.7.1 or later
- BThe Power 770 requires an HMC (7042-CR5 or later), so they must buy one. All of the systems can be managed by this new HMC
- CThey should buy a new HMC for the Power 770 system, and leave the POWER5 and POWER6 based systems connected to the existing one
- DThe Power 770 requires an HMC, so they should connect the Power 770 to the HMC and convert the POWER5 and POWER6 based servers to IVM