Answer:
d.The wavelength of light and the size of the aperture
Explanation:
<em>The resolution power of an optical system is the smallest distance between two points that the device can distinguish clearly.</em>
It has the following relationship:

where:
r = minimum resolvable distance
n = numerical aperture
= wavelength of the light used for viewing
From above mathematical equation it is clear that:
- Smaller the wavelength better the resolving power
- Larger the aperture better the resolution
(Note, that smaller the value of "r" the more finer details of the image visible through the device.)
81°.
The law of reflection states that the angle of incidence is equal to the angle of reflection.
They spill out chemicals into our air that may be bad for our lungs