Answer:
The independent (or manipulated)variable is something that the experimenter purposely changes or varies over the course of the investigation. The dependent (or responding) variable is the one that is observed and likely changes in response to the independent variable.
Explanation:
please mark as brainlist answers
I've checked all the options and I think that the right answer looks like this: M<span>ollusks</span> have highly developed olfactory receptors.
