Final answer:
Pneumatic tools should not be carried by the air hose as it can cause damage and accidents.
Step-by-step explanation:
ANSWER: a. air hose
Pneumatic tools should not be carried by the air hose because it can cause damage to the hose and potentially lead to accidents. The air hose is not designed to bear the weight of the tool, and carrying it by the hose increases the risk of it being stretched, twisted, or punctured.
Instead, pneumatic tools should be carried by their designated handles or grips, if available. If not, it is recommended to transport them in an appropriate carrying case or toolbox to ensure their safety and longevity.