Which of the following is an example of diffraction?
you are able to see yourself in a mirror.
you can hear a smoke alarm located in the hallway from your bedroom.
you try to pick up a shell in the water but it isn't where it appears to be.
the speed of your car is determined using radar.

You try to pick up a shell in the water but it isn't where it appears to be is an example of diffraction

Explanation:

Diffraction refers to the light bending that happens as the light passes about the edge of some object. How much bending takes place is found by the size of wavelength of light relative to that of opening. If the opening is larger than the wavelength of light, then bending will not be noticeable.

Since, light gets diffracted due to water hence the shell kept inside the water appears to be at a different position than where it actually is

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

explanation:

yes you are doing it right great gob