Which of the following best describes the efficiency of dry scrubbers at removing particles that are less than 2 micrometers in diameter? Dry scrubbers are less than 20% efficient at removing particles less than 1μm and increase to over 50% efficiency at removing particles between 1 and 2μm. A Dry scrubbers are between 50% and 90% efficient at removing particles less than 2μm, depending on the flow rate. B Dry scrubbers are between 5% and 40% efficient at removing particles less than 2μm in size. C Dry scrubbers are less than 10% efficient at removing particles less than 1μm in size.