B or d.... hope this helps:)
Answer:
B) cells or tissue that produce light
Explanation:
It wouldn't be A because photophores do not affect the color of other organisms.
It wouldn't be C because the cells produce light, they don't necessarily change color.
Lastly, it wouldn't be D because it isn't a whole organism producing the light, it's an organ. Organs are multiple tissues working together, and tissues are groups of cells.
Answer : Option A) He asked what would happen if he deliberately inoculated someone with cowpox fluid from another person.
Explanation : Edward Jenner wanted to know what would happen if he deliberately inoculate the cowpox fluid from some person to another. He tested this experimental results and later on came up with the hypothesis. Which roughly state that someone will not get smallpox because they already had cowpox.