I think the answer is B
Beacuse It follows the successful completion of S phase, during which the cell's DNA is replicated. Mitosis is a part of the cell cycle process by which chromosomes in a cell nucleus are separated into two identical sets of chromosomes, each in its own nucleus.
Mitochondria, plastids and chloroplast all are surrounded by a double membrane
This part of the experiment serves as basis of comparison; the one variable being tested has been omitted Experimental group.This part of the experiment shows the effect of the one variable being tested.Independent variable.This variable is an experiment is the one being deliberately changed by the scientist.
"Denatures" is the word you are looking for!