Assume you have the following files: Employee with 6000 records and 2000 blocks. Department with 50 records and 5 blocks. Assume that the available buffer space=7. (Show your work) A) Calculate the cost (block access) using "Nested-loop join" technique of the following query: (Employee Dno=Dnumber Department) [3 POINTS]. - Suppose the secondary indexes exist on both the attributes Ssn of Employee and Mgr_ssn of Department, with the number of index levels xSsn=4 and xMgr_ssn=2 respectively. B) Calculate the cost (block access) using "Single-loop join" technique of the following query: (Department MGRSSN =SSN Employee) [2 POINTS]. -Suppose that both files need to be sorted. C) Calculate the cost (block access) using "Sort-merge join" technique of the following query: (Employee Dno=Dnumber Department) [3 POINTS]