2.(10%) This back-calculation equation below has been used in Australia to get the total consumption (doses per day per 1000
people) of illicit drugs used in the community, where concentration (analyte) of illicit drugs is measured in the
wastewaters. Assuming that we can use similar equation to estimate the exposure to COVID-19 in the community, in the
case where we don't have "Flow volume" and "Catchment population in 1000's" data, what other data can be used
instead? In other words, which parameters in the wastewaters can be used as biomarkers to represent/indicate
wastewaters that were originated from human usage instead of other sources (i.e. rain water, industrial wastewaters,
etc)? (Please select the least appropriate or the least suitable biomarker)

a.BOD (Biological Oxygen Demand
b. Ammonia Nitrogen
c. Total Nitrogen
d. Total Phosphorus
e. Total Carbon