Q: According to recent studies, bananas are the most promising food for an edible vaccine against the hepatitis B virus,
A) but this virus is very common in many African countries
B) so that potatoes, tomatoes and other vegetables might serve to immunize people some day
C) just as symptoms of acute viral hepatitis usually begin suddenly
D) which lives in about 5 per cent of the world's population
E) whereas scientists have discovered a way to boost the level of immune-triggering hepatitis protein in the fruit
This is the question. I am asked to complete the sentence. The given answer is E. I think the answer should be D.
This is what I think about the question:
D seems to be the correct answer because it explains Hepatitis B virus. E, however should be wrong because "whereas" doesn't really go well with the rest of the sentence. Can you explain if I am wrong? Thanks.