Database-level role name
Description
db_owner: Members of the db_owner fixed database role can perform all configuration and maintenance activities on the database, and can also drop the database.
db_securit yadmin: Members of the db_securityadmin
fixed database role can modify role membership and manage permissions.
Adding principals to this role could enable unintended privilege
escalation.
db_accessadmin: Members of the db_accessadmin fixed database role can add or remove access to the database for Windows logins, Windows groups, and SQL Server logins.
db_backupoperator: Members of the db_backupoperator fixed database role can back up the database.
db_ddladmin: Members of the db_ddladmin fixed database role can run any Data Definition Language (DDL) command in a database.
db_datawriter: Members of the db_datawriter fixed database role can add, delete, or change data in all user tables.
db_datareader: Members of the db_datareader fixed database role can read all data from all user tables.
db_denydatawriter: Members of the db_denydatawriter fixed database role cannot add, modify, or delete any data in the user tables within a database.
db_denydatareader: Members of the db_denydatareader fixed database role cannot read any data in the user tables within a database.
Fonte: https://msdn.microsoft.com/en-us/library/ms189121.aspx
a) ERRADA. current_user não é um tipo de database role
b) CORRETA. Os membros da função de banco de dados fixa db_owner podem executar todas as atividades de configuração e manutenção no banco de dados, bem como remover o banco de dados.
c)ERRADA. tempdb é um banco de dados do sistema
d) ERRADA. sp_who não é um tipo de database role.
e) ERRADA. masterdb é um banco de dados do sistema