Who is accredited for the discovery of penicillin?

A. Escherichia: This bacterial genus includes Escherichia coli, a common cause of urinary tract infections and gastrointestinal illness, but it does not cause pinworm disease.

B. Enterococcus: These bacteria are part of the normal gut flora and may cause opportunistic infections, but they are not responsible for pinworm infestation.

C. Enterobius: Enterobius vermicularis is the causative agent of pinworm infection, a helminthic disease spread via the fecal–oral route and characterized by perianal itching, especially at night.

D. Entamoeba: Entamoeba histolytica is a protozoan parasite that causes amoebiasis and dysentery, but it is unrelated to pinworm disease.

A. growing corn plants with various amounts of fertilizer: Using corn plants introduces a different species, which makes results irrelevant to the effect of fertilizer on tomato plants.

B. growing tomato plants with various amounts of fertilizer: This is part of the experimental group rather than a control, as it tests different fertilizer levels rather than providing a baseline for comparison.

C. growing corn plants without fertilizer: Corn plants are not suitable because the research question focuses on tomato plants. A valid control must match the species being studied.

D. growing tomato plants without fertilizer: This is the correct control, as it provides a baseline growth rate for tomato plants without fertilizer, allowing meaningful comparison with fertilized groups.