The answer is B the flow of electrons through a substance
An educated guess is called estimation
Because flammable objects have certain substances, you know that it is a chemical property. For example, cloth is flammable and has a certain substance that MAKES it flammable. This results in a chemical property.
Atoms are electrically neutral because they contain equal quantities of positively charged protons and negatively charged electrons. Electrons and protons have equal but opposite charges, so the result is no net charge. Ions are atoms that have gained or lost electrons.