The correct answer is C. Ronald Ross.
Ronald Ross was a British physician and parasitologist who won the 1902 Nobel Prize in Physiology or Medicine for his discovery of the life cycle of the malaria parasite. He was the first person to demonstrate that malaria is transmitted by mosquitoes.
Patrick Manson was a Scottish surgeon and physician who is considered the father of tropical medicine. He was the first person to demonstrate that mosquitoes can transmit human diseases, including malaria.
Charles Louis Alphonse Laveran was a French physician and biologist who won the 1907 Nobel Prize in Physiology or Medicine for his discovery of the malaria parasite.
Richard Friedrich Johannes Pfeiffer was a German physician and bacteriologist who discovered the bacterium that causes cholera.
Here is a brief description of each option:
- Option A: Patrick Manson was a Scottish surgeon and physician who is considered the father of tropical medicine. He was the first person to demonstrate that mosquitoes can transmit human diseases, including malaria. However, he did not discover the life cycle of the malaria parasite.
- Option B: Charles Louis Alphonse Laveran was a French physician and biologist who won the 1907 Nobel Prize in Physiology or Medicine for his discovery of the malaria parasite. However, he did not discover how the malaria parasite is transmitted.
- Option C: Ronald Ross was a British physician and parasitologist who won the 1902 Nobel Prize in Physiology or Medicine for his discovery of the life cycle of the malaria parasite. He was the first person to demonstrate that malaria is transmitted by mosquitoes.
- Option D: Richard Friedrich Johannes Pfeiffer was a German physician and bacteriologist who discovered the bacterium that causes cholera. He did not contribute to the discovery of the life cycle of the malaria parasite.