Which piece of evidence would most likely be relevant to this research question?

Does the world have a responsibility to make sure poor countries have enough medicines for their people?

A. Most children in the United States have access to health care even though it can be very expensive.

B. Medical care has saved millions of people from a number of deadly diseases over the past 100 years.

C. According to a health expert, the whole world will be safer if everyone can effectively fight certain diseases.

D. One of the world's first effective vaccines was developed by a country doctor in England in the 1700s.

C. is correct.​