I think it’s B) Molecules
I searched it up
Explanation:
Alkanes are the simple hydrocarbons that have only carbon and hydrogen atoms attached to each other through single bonds.
General chemical formula of an alkane is 
, where n is any integer.
For example, if n = 5 then formula of the alkane will be as follows.
= 
= 
A suffix "-ane" is added in the name of an alkane. So, an alkane with five carbon atoms will be known as pentane.
In salt water solution, the salt is the solvent.
I don’t understand the question
Answer: Refrigerator and fire extinguisher
Explanation: Refrigerator:An evaporator fan draws air from the refrigerator and blows it over the evaporator coils. The liquid refrigerant absorbs heat from the air and the air blows back into the refrigerator at a lower temperature, cooling the refrigerator. The liquid refrigerant starts to vaporize as it heats up and moves to the compressor.
Fire extinguisher:They work by smothering the fire: when you put a layer of powder or foam on the fire, you cut the fuel off from the oxygen around it, and the fire goes out. Carbon dioxide (CO2) extinguishers contain a mixture of liquid and gaseous carbon dioxide (a nonflammable gas).
