1. Given the following relations and referential integrity rules, draw an ER diagram on the following blank page. Make assumptions where necessary but be sure to list any assumptions made. Show each assumption with a capital A inside a circle. Assumptions cannot be made in contradiction to the given relations and foreign key constraints. (Primary keys are underlined, foreign keys are bold). TROLL(TrollName, FootColor, BeardLength, TrollType, SupervisorName) Foreign Key Supervisor Name references Troll(TrollName) Null Allowed, On Delete Set Null BRIDGE (Bridgeld Name, Length, Toll, TrollName) Foreign Key TrollName references Troll(TrollName) Null Allowed, On Delete Restrict ROUTE(Bridgeld CityName Distance, Road Condition) Foreign Key Bridgeld references Bridge(Bridge) Not Null, On Delete Restrict Foreign Key CityName references City/CityName) Not Null On Delete Restrict CITY(CityID, Population, Odorindex) COUNCIL(Cityname ChampName ManagerID, HappyLevel, City Ratio, Champ Ratio, Mgr Ratio) Foreign Key City Name references City/CityName) Not Null On Delete Restrict Foreign Key ChampName references Champion(ChampName) Not Null On Delete Restrict Foreign Key Managerlo references Manager (Manager) Not Null On Delete Restrict CHAMPION(ChampName, WSBI, Trope, HorseName) MANAGER Manageri CMSL, FirstName, LastName, Street, City, Sector) SKILLSET(SkilletiD, Manager D, Skillid, DateLearned, Location, Payment) Foreign Key ManageriD references Manager(Manager) Not Null, On Delete Restrict Foreign Key Skilli references Skill(skillib) Not Null, On Delete Restrict SKILL(SkillID, RetailCost, MasteryHours)