Read the following statements and answer the question that follows.

A. Whatever that might be on Europa—far from the Sun, and beneath kilometers of ice
—it will not be sunlight.
B. The final ingredient for a habitable world is a source of energy for life to exploit.
C. On Earth almost every living thing ultimately depends on photosynthesis for its
energy, including the rich ecosystems in the ocean depths, discovered in the 1980s and
which helped the idea of life on Europa gain a foothold.
D. Their inhabitants do not benefit from sunlight directly, but their metabolisms are
powered by chemicals created in the photosynthesizing, oxygen-rich surface oceans
far above.
E. That is a bit of a problem.

Which of the following sequences is the MOST logically ordered?