Answer is 1 table , option A
NOTE:- A: Deptno, B: DName, C: Phone and D: Office
Q) min table for 1 NF?
Sol) 1 table Dept(ACDB)
ACD as CK
Q) min table for 2 NF/ 3 NF / BCNF?
Sol) 2 table Dept1(AB) and Dept2(ACD)
CK: A for Dept1 and for Dept2: ACD
Q) min table for 4 NF?
Sol) 3 table Dep1 (AB) , Dept2(AC), Dept3(AD)
CK: A