I think it is D
Hope my answer help you?
Liter
The Basic Unit for Volume
The liter, which is the basic unit of volume, was originally defined as the volume occupied by 1 kilogram of water, but today it's simply one-thousandth of a cubic meter
BRAINLY PLS
Answer:
The width of the central bright fringe on the screen is observed to be unchanged is 
Explanation:
To solve the problem it is necessary to apply the concepts related to interference from two sources. Destructive interference produces the dark fringes. Dark fringes in the diffraction pattern of a single slit are found at angles θ for which

Where,
w = width
wavelength
m is an integer, m = 1, 2, 3...
We here know that as
as w are constant, then

We need to find
, then

Replacing with our values:


Therefore the width of the central bright fringe on the screen is observed to be unchanged is 
To the picture the answer is A. I can’t answer the typed question because I need the picture for the box