GMAT Critical Reasoning (CR) | Re: Chema Options to Reduce Emissions

Chema is a factory that creates plastics and plastic related products for the chemical and pharmaceutical industries. It has two options to reduce harmful emissions from its factory - installing scrubbers in its smokestacks and switching to cleaner-burning fuel. Since scrubbers can reduce more harmful emissions than cleaner-burning fuels can, Chema is doing the most it can do to reduce harmful emissions from its factory by installing scrubbers.

Which of the following is an assumption on which