Do explain. QUESTION:- If the breast cancer cells treated with CBD extract, which of the following would not be a controlled variable? a. PH buffering of the growth medium. b. Solvent used to dissolve...

Do explain.

QUESTION:-

If the breast cancer cells treated with CBD extract, which of the following would not be a controlled variable?

a. PH buffering of the growth medium.

b. Solvent used to dissolve CBD extract.

c. Number of cells per plate after treatment.

d. Temperature inside incubator where the cells are grown.