(c) People who do not have diabetes maintain their blood glucose concentration below

Suzie can measure the HEIGHTS of the plants in metres (m) or centimeters (cm)

Explanation:

According to this question, Suzie Q wants to know how different colors of light effect the growth of plants. She sets up the experiment by exposing 5 ferns of the same species to different colors of light (white, blue, green, red).

After ensuring that some variables called constants like same 20 mL of water, same fertilizer (miracle-grow) etc are the same for all ferns, She then measures the growth of each fern placed under different colors of light.

The independent variable in this experiment is the different colors of light while the dependent variable is the growth of the plants. This question is asking for how Suzie could measure the dependent variable (growth). Suzie can measure the growth of the ferns placed under different colors of light by RECORDING THE HEIGHTS OF EACH FERN IN cm or m.