If you look at the light spectrum reflected from the surface of a DVD compared to the spectrum reflected from the surface of a CD, you'll see that the rainbows from the DVD are more spread out, with greater angular separation. Fill in the Blanks.
1. Tracks on disks act as a _____.
2. The distance between tracks d is related to the angular dispersion of bright peaks according to _______.
3. Increasing the spacing d means decreasing _________, which means ________ θ m for 0 < θ m < 90 ∘ .
4. So the fact that the light reflected from the DVD is more spread out than the light reflected from the CD means that the distance between tracks must be smaller for the ______.

Choices are :
A. dcosθm=mλ
B. refractive prism
C. cosθm
D. decreasing
E. CD
F. DVD
G. sinθm
H. reflection grating
I. increasing
J. dsinθm=mλ