The particles in the wave separated through __________ multiple of ? are out of phase to each other

The particles in the wave separated through __________ multiple of ? a

1.	The particles in the wave separated through __________ multiple of ? are out of phase to each other
A.	(n)
B.	(n+1)
C.	(n+1/2)
D.	Both (a) and (c)
Answer» D. Both (a) and (c)