Question

multiple choice question
a ______ is a simple way of measuring light attenuation by lowering it into water until it just disappears from sight.
o secchi disk
o clarity wheel
o sverdrup lens

Explanation:

A Secchi disk is used to measure water transparency which is related to light attenuation by lowering it into water until it disappears from sight. There is no such thing as a clarity wheel in this context, and a Sverdrup lens is not used for this purpose.

Answer:

A. Secchi disk