There Are Tubeworms and Clams That Live at the Bottom

There are tubeworms and clams that live at the bottom of the ocean near thermal vents that do not have direct access to sunlight so they derive their energy from

A) the sun by way of burning fossil fuels like we do with coal and oil.
B) the sun,but they are deep in the dark ocean and live off dead detritus that sink to them.
C) chemosynthetic bacteria.
D) sources not yet known.