A 50% to 90% death rate means that a disease is very

Case fatality rate, in epidemiology, the proportion of people who die from ... Case fatality rate typically is used as a measure of disease severity and ... In Fact Britannica shares some of the most bizarre facts we can find. ... 0.04, or 4 percent; the case fatality rate, however, is 40 ÷ 50 = 0.8, or 80 percent.

Explanation:

so we know the answer cannot be c because no insect or animal starts as an adult

the answer is a. a swimming larvae

because since they are sea animals they automatticaly have to know how to swim they cannot just sink to the bottom

sorry if this is the incorrect answer.

c.a.

explanation: