7. A database is planned to consist of the following relations. New relations will not be added to the database. New information may be added to relations. TEACHING ASSISTANT TA ID NAME TA1 SMITH TA2 ZHANG TA3 LIU DEPT NO D1 D2 D1 UCSB DEPARTMENT DEPT NO DI D2 NAME SOCIOLOGY GEOGRAPHY OFFICE TA ID TA1 TA2 TA3 OFFICE SH 01 SH 02 SH 01 PHONE EXT 345 454 345 A) For the above database identify the following: a) domains b) candidate and primary keys c) foreign keys