For a Certain Multiple-Slit Barrier the Slit Separation Is 4

Multiple Choice

For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system:

A) the orders of the lines that appear are all multiples of 4
B) the orders of lines that appear are all multiples of 2
C) the orders of the missing lines are all multiples of 4
D) the orders of the missing lines are all multiples of 2
E) none of the above are true