The best answer is (1)
Fossil fuels are commercially available as an energy source.
They are very easy to find. More and more extractions of fossil fuels is going on everyday. With advancement in science and technology, the refineries and extraction procedures have improved a lot. This makes their availability even better.
Fossil fuels are also easily combustible. Most combustion engines need to be powered with little amount of fuel to produce large amount of energy. Very large amounts of electricity can be generated from fossil fuels.
C is the answer. Due to the current state of the world economy; people, if left to their own devices, would fish as much as possible so they can sell their fish to make money. Current technology means we can catch as many fish as we want (trawlers etc.). The problem with this is that there is only a finite amount of fish in the sea. If we were to fish them without limits in place, we could cause them to go extinct.
Some characteristics that is shared is a soft body and an outer shell to protect their body.
