Which of the following is an example of chemical damage to a fire hose?

Chemical damage to a fire hose occurs when the hose comes into contact with substances that can corrode or degrade the materials it is made from. Battery acid is a strong corrosive substance that can react with the materials of a fire hose, leading to significant deterioration. This degradation can weaken the hose's integrity, making it unsafe for use in firefighting operations. The other options do not represent chemical damage. Water can potentially cause physical wear or mildew if left untreated but does not cause chemical deterioration. Air pressure relates more to physical stress than chemical damage, and smoke, while potentially harmful in other ways, does not usually chemically corrode the hose material in the same way as corrosive chemicals do.