Question

signs that say \do not use near an open flame\ refer to a(n)
a energy property
b chemical property
c physical property
d mechanical property.

Explanation:

A chemical property is a characteristic of a substance that is observed during a chemical reaction. Signals like "do not use near an open flame" imply that the substance can react with oxygen in the air (burn) which is a chemical reaction. So it refers to a chemical property.

Answer:

B. chemical property