4. A blue light is shined on objects X and Y. Object X appears to be blue, and object Y appears to be black. Which of the following is correct?
A. Object X absorbs blue light, and object Y reflects blue light.
B. Object X reflects blue light, and object Y absorbs blue light.
C. Object X must be black, and object Y must be blue.
D. Object X must be blue, and object Y must be black.

The Answer is B

Explanation:

Objects that appear blue reflect blue light

and objects that appear black must absorb blue light

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

a is the correct answer