EAp2 and EAc1.3

Hi, I am new to LEED CI and am confused about a couple of things. Is it allowed to choose to meet the requirements of section 11 through an energy model for the prerequisite and use option 1 for EAc1.3 or should an energy model be used for both the prerequisite and the credit? Our plan is to use an energy model for the prerequisite since we are the design team and will put together a model for load estimates and use option 1 for the credit since we are not sure if we can achieve 30% savings which seems like a tall order for a CI project. Thanks a lot!