Scientific studies on bioelectric effects primarily focus on the following: nerve or muscle tissue, electric organs in certain fish, the effects of damaged tissue, and such organs as the heart, ear, stomach, and brain.
Solution:
Really tricky one but I went more with removing certainties and then checking the unusual ones because similar ones or that had little difference could not be both correct. So, B and C had this ";" directly after following which I think is absolutely wrong. We cannot just cut the sentence after mentioning we are presenting something like the following. Now A and E, I could not find any big difference like they are very similar, so i went with D.
(A) following: nerve or muscle tissue, electric organs in certain fish, the effects of damaged tissue, and such organs as the heart, ear, stomach, and brain.: I eliminated this because there are too many commas and it becomes confusing to know the parallel list.
(B) following; nerve or muscle tissue, electric organs in certain fish, the effects of damaged tissue, and such organs as the heart, ear, stomach, and brain.: can't abruptly end with ";" after following
(C) following; nerve or muscle tissue; electric organs in certain fish; the effects of damaged tissue; and such organs as the heart, ear, stomach, and brain.: can't abruptly end with ";" after following
(D) following: nerve or muscle tissue; electric organs in certain fish; the effects of damaged tissue; and such organs as the heart, ear, stomach, and brain.: the process of elimination
(E) following: nerve or muscle tissue, electric organs in certain fish, the effects of damaged tissue, and organs including the heart, ear, stomach, and brain.: I eliminated this because there are too many commas and it becomes confusing to know the parallel list.