It’s an illusion to make you think the caterpillar is green but it actually is every other color but green
Marcello Malpighi was the person who used a microscope to see blood capillaries in the tail of a fish.
He was a famous Italian scientist of the 17th century, and is known as 'the father of microscopical anatomy, histology, physiology, and embryology,' so he is definitely the correct answer. Many terms in biology are actually named after this biologist.
The patient could possibly have contracted some sort of foreign disease or might simply have an intolerance to a certain protein such as gluten with celiacs disease.
The correct answers are B. and C.