I need help with this chemistry question talking about pure substances and mixtures?

The correct answer is A. The sample is not a heterogeneous mixture

Explanation:

A heterogeneous mixture includes two or more materials and these are not completely integrated. Due to this, in most cases, if a heterogeneous mixture is filtered it is possible to separate its parts. This did not occur when Ben filtered the substance, which shows it is likely the substance is not a heterogeneous mixture. Moreover, a heterogeneous mixture does not show uniformity in terms of appearance or properties, which shows this definitely not heterogenous and Ben can safely conclude this.

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.