In quadrantal bearing system, back bearing of a line may be obtained from its forward bearing, by

adding 180 , if the given bearing is less than 180

subtracting 180 , if the given bearing, is more than 180

changing the cardinal points, i.e. substituting N for S and E for W and vice-versa

In quadrantal bearing system, back bearing of a line may be obtained f

1.	In quadrantal bearing system, back bearing of a line may be obtained from its forward bearing, by
A.	adding 180 , if the given bearing is less than 180
B.	subtracting 180 , if the given bearing, is more than 180
C.	changing the cardinal points, i.e. substituting N for S and E for W and vice-versa
D.	none of these.
Answer» D. none of these.