Dr. Zakaria Test devciamayoring i ififlantpe=nati) frum null: 1. iffolant ye equalulmovaCase TDomesticruas"n f. return now Dorsoricilan0: 1 1 else if(planType cqualslgnoreCase;'DSTIUTONMLPLNNT) 1. retum new InstitutionalPlan0 0 1. retum null; Create the following three Concrete classes that evtends Plan abstract claws. a) DomesticPlan, InstitutionaIPlan, CommercialPlan b) Each plan retums the rate at which elecincity bill can be paid. Sach ax, for Sonsetcqlate pate is 3.5, for InstitutionalPlan is 5.5 and CommercialPian is 5.5 Answer: class DomesticPlan