Sentence Correction

Can someone comment on the grammar structure of 1 through 3? Which one is correct / incorrect? And what is the implied meaning of each. Thanks.

1) Nuclear fusion is the force that powers the Sun, the stars, and hydrogen bombs, merging the nuclei of atoms and .....
(merging here expands on the idea of what NF does)

2) Nuclear fusion is the force that powers the Sun, the stars, and hydrogen bombs, and merges the nuclei of atoms and .....
(Seems to imply NF does two separate things: 1) powers and 2) merges)

3) Nuclear fusion is the force that powers the Sun, the stars, and hydrogen bombs, and that merges the nuclei of atoms and .....
(Do you need "that" here? I've seen this structure a lot and it is correct: X is the thing that does Y, modifier, and that does Z. Does it apply here? [Not that " the stars, and HB" is the modifier of the Sun])? Difference between 2 and 3?

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Original Problem:

Nuclear fusion is the force that powers the Sun, the stars, and hydrogen bombs, merging the nuclei of atoms and not splitting them apart, as in nuclear reactors.

(A) merging the nuclei of atoms and not splitting them apart, as in nuclear reactors
(B) merging the nuclei of atoms instead of splitting them apart, like nuclear reactors
(C) merging the nuclei of atoms rather than splitting them apart, as nuclear reactors do
(D) and merges the nuclei of atoms but does not split them apart, as is done in nclear reactors
(E) and merges the nuclei of atoms, unlike atomic reactors that split them apart