Pollution of a river as a byproduct of paper manufacturing is considered a(n)

a. natural resource

b. negative externality

c. internal benefit

d. human capital

e. external benefit

B. Negative externality

Explanation:

An externality is defined as a benefit or a loss that occurs to a third party due to some external reasons. The party has no control over the creation of the benefit or loss. It can be both negative or positive. Negative externality is a loss caused to the party whereas positive externality is a benefit caused to the party.

Here, the river is being polluted due to paper manufacturing industry. It means that the river is incurring a loss due to an external factor. Hence, this situation would be considered as negative externality.  

the cell theory states that all living things including animals, as well as plants, are made of cells.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.