All of the following are indicators of low social welfare except
a. high infectious disease rates
b. inadequate sewer systems
c. high literacy rates
d. large numbers of child laborers

i dont know but thats a great qusestion

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.