Answer:
The independent variable is "controlled" or held constant in the control group.
Explanation:
The answer is
B, a euglena uses a flagella in order to move. Euglena is a one celled organism
under the Kingdom Protista. A flagella (or flagellum plural) is a long strand
like structure that is located in the front end part (more like a tail in front).
It flips to the left and right in order for the organism to move. It is
connected to the reservoir, which contains the storage of food for the
organism.
