Which behavior was observed when one end of the earthworm was placed on a wet paper towel while the other end was placed on a dry paper towel?

Earthworms need moist skin for gas exchange and tend to move toward moist conditions. So, whether its anterior or posterior end began on the wet towel, it moved until its entire body was on the wet paper towel. This matches the choice stating that it went to the wet towel regardless of which end started there.

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