Which of the Following Best Explains Why an Interstellar Ramjet

Multiple Choice

Which of the following best explains why an interstellar ramjet could,in theory,achieve continuous acceleration?

A) It uses fuel that is more efficient than any other known fuel.
B) It collects its fuel as it goes,rather than having to carry the weight of fuel along with it.
C) It takes advantage of theoretically possible loopholes in Einstein's theory of relativity.
D) It has such a large fuel tank that it will essentially never use up all the fuel it carries.
E) Its speed always gets faster because the effects of time dilation change the rate at which time flows.