Answer:
If research demonstrates that malaria cannot infect dogs, the author's claim that mosquitoes are essential to the life-cycle of the malaria parasite would be: D. clearly rebutted.
This is because the author's claim that mosquitoes are essential to the life-cycle of the malaria parasite is based on the idea that mosquitoes transmit the parasite to humans and animals, including dogs. If it is shown that dogs cannot be infected with malaria, this would contradict the claim that mosquitoes are essential to the life-cycle of the parasite, as they would not be able to transmit the parasite to this host. Therefore, the claim would be clearly rebutted by this research.
Step-by-step explanation: