Punctuation: Dialogue that trails off and picks up again

I would suggest writing this in either of the following ways:

"Something about the way she smells . . ." The man breathed in deeply, a smile spreading across his face. ". . . just drives me wild."

Practically identical to your A, except most advice would suggest that the ellipsis should be written with spaces before, after and between each dot, except where other punctuation occurs. Alternatively, there is an ellipsis glyph (…).

"Something about the way she smells"—the man breathed in deeply, a smile spreading across his face—"just drives me wild."

Almost like your C, except the em dashes are outside of the quoted material.

Also, on an unrelated note, I would prefer the use of deeply here. Using an adjective where an adverb belongs is very American and while not strictly incorrect—especially when used informaly—I would avoid it.

These suggestions are in agreement with this article, which uses a very similar structure in the section What advice did I give to the reader who emailed with the question about ellipses? Although, that article avoided using the ellipsis a second time and reinserted the subject as a pronoun for the second half of the quote as, for example, "She just drives me wild", but that seems to change the sense of the breakage somewhat.

I admit I hesitated over the first suggestion here and edited multiple times, which leads me to prefer the second.