Read the following essay, which lacks a conclusion: Dengue fever is the most common mosquito-borne disease in the world, infecting 100 million new victims every year. In the
1950s, mosquito control efforts and public health campaigns drove this illness from the U. S. Now, it's back. Dengue has
reappeared in Florida, Texas, and Hawaii, and it is spreading.
Although it's usually not fatal, there is no vaccine or cure. Sometimes called breakbone fever because of the extreme joint
pain it causes, dengue also brings rashes, blistering fever, and sometimes bleeding, organ failure, and shock. A recent study of
the illness concluded that "Dengue fever most likely will become a disease the United States must learn to live with as climate
change creates opportunities for the disease to gain a foothold." Even more troubling, dengue fever is not alone.
Over the past several decades, infectious disease cases have risen in step with the temperature. Milder winters and wetter
springs in many parts of the warming world have led to mosquito and tick population booms. These insects can be active
during more months of the year, and in some areas, they are now able to survive where winter freezes used to kill them off. As
they have spread, so have the diseases they carry, including Lyme disease, malaria, encephalitis, yellow fever, West Nile virus.
Which of the options below is the most effective conclusion to the essay?