Database Management - Relational Algebra Question

StaffMember(Uniqname, FirstName, LastName, Role, CityID) City (CityID, CityName, StateOrProvince, Country) Fruit(FruitID, Name, VitaminC) Enjoys(Uniqname, FruitID) Note: The VitaminC attribute of the Fruit table represents the milligrams of vitamin C that the fruit contains. The CityID field of the StaffMember table refers to the hometown city of staff members. The Enjoys table stores data on which staff members enjoy which fruits. Given the above schema, write relational algebra statements for the following statements: A. Find the first and last names of all staff members whose hometown city is in the country China and who enjoy the fruit whose name is durian (5 points) B. Find the name and country of all cities that are NOT a hometown of any staff member whose role is GSI. (4 points) C. Find the uniqnames of all staff members who enjoy the fruit named "Mango' or are from the state of Ohio'. (4 points)