Which of the following best describes ACQ, MCQ, and CA-C?

The correct choice identifies ACQ (Alkaline Copper Quaternary), MCQ (Micronized Copper Quinolate), and CA-C (Copper Azole, Type C) as preservatives used in wood treatment, specifically in deck construction. These wood preservative chemicals have been developed to replace CCA (Chromated Copper Arsenate), which has been phased out for residential use due to environmental and health concerns.

ACQ, MCQ, and CA-C provide effective resistance against decay and insect damage like CCA but are formulated with less toxic components, making them preferable in settings that require safety and environmental considerations. Each of these preservatives offers varying levels of performance and environmental impact, but they all share the common trait of being less corrosive to metals compared to CCA.

They are specifically designed for treating wood, particularly in applications such as decking, fencing, and outdoor structures, thus making them the best candidates under the wood treatment category. Recognizing the focus on wood treatment helps clarify that the materials in question are integral to ensuring the longevity and durability of outdoor wooden structures.