Which of the following definitions describes a chemical hazard?
a. can be present in dust, fumes, liquids, solids, mists, vapors, or gases of products used at a site or released during a construction job
b. microorganisms, such as bacteria, fungus, mold, or viruses that can cause illness
c. the most commonly thought of hazards for construction
d. these hazards can lead to injuries to the joints or muscles by way of heavy, frequent lifting, repetitive tasks