Which of the following statements is true about Class A fire extinguishers?

Class A fire extinguishers are specifically designed to combat fires involving ordinary combustible materials. This class includes materials such as wood, paper, textiles, rubber, and many plastics. The effectiveness against wood as stated in the correct answer is rooted in the capabilities of these extinguishers, which typically use water or water-based agents to cool and extinguish fires involving such solid combustibles.

In contrast, while Class A extinguishers can sometimes handle textiles, the extent to which they are effective can depend on the nature of the textile and its treatment—hence the importance of specifying their primary focus on solid combustibles like wood. Furthermore, Class A extinguishers are not suitable for use on electrical fires or flammable liquids, which are addressed by other classes of extinguishers. Therefore, the assertion that Class A extinguishers are okay for wood directly aligns with their intended use and classification.