Scarlet fever or scarlatina is an infection for those people having sore throat. It's symptoms usually is a bright red rash with fever as well as sore throat. It affects children from 5-15 years old. It is cause by the streptococcus pyogenes. It's mode of transmission is droplet and direct contact and the virulence is cause by erythrogenic toxin.
The opposite of an echosystem is Chaos pollution and exosytem
Detritivores role is to consume dead animals (decompose). Thus it is B