Answer:
Optical axis
Step-by-step explanation:
Optical axis is the rotational symmetry axis of the surfaces.
A line with a certain degree of rotational symmetry is called as the optical axis in an optical system.
It is the straight line that passes through the geometric center of the lens and joins two curvature centers of its surfaces.
It is also called as the principal axis.
Answer:

-8 to the power of 0 = 1
(Anything to the power of 0 = 1)
and 6 to the power of -1 = 1/6
( Any number to the power of a negative number will become a fraction)
Example.

So is will be 1/6 over 1
Which gives you your final answer.
Nope .42 is greater, .4 is closer to 1 then .2 have a great day and hope this helps
Answer:
C)
Step-by-step explanation:
Just see the length of the R line, A and B are almost the same large when you add them.