Three coils are connected as in the following figure with self-inductances and mutual inductances as indicated. The effective inductance of the circuit across the terminal AB in the figure, is

Three coils are connected as in the following figure with self-inducta

1.	Three coils are connected as in the following figure with self-inductances and mutual inductances as indicated. The effective inductance of the circuit across the terminal AB in the figure, is
A.	9 H
B.	21 H
C.	11 H
D.	6 H
Answer» D. 6 H