Which of A-D Is a Disadvantage in Using Hydrogen Fuel

Which of A-D is a disadvantage in using hydrogen fuel cells instead of gasoline engines in vehicles? If all are valid disadvantages, respond E.

A) It is difficult to store hydrogen safely.
B) No distribution network of hydrogen fuel is in place.
C) Hydrogen fuel must be produced, most likely from water, by using another energy source.
D) Hydrogen fuel is not really a source of energy, but rather is a way to store energy.
E) All of the above.