Hydrocarbons are most useful as a source of stored:

a. carbon

b. hydrogen

c. energy

d. medicines

Hydrocarbons are most useful as a source of stored C. Energy.

I think the correct answer from the choices listed above is option C. Hydrocarbons are most useful as a source of stored energy. Energy is stored in these compounds as chemical energy through the bonds present in these substances. Hope this answers the question. Have a nice day.