Wrong answer
The correct answer for this question must be however based on the prompt's structure:
Let "The researchers did not perform this analysis on all such ungulates" be clause A, "they focused exclusively on elk in Wyoming" be clause B, and the preceding sentence "In a 1993... North America ungulates" be clause C.
We have the structure: C. A, (blank); B
Given this placement of the comma (,) and semicolon (;), the word in the blank describes the relationship between clauses A and C -> therefore, the answer is however;.
On the other hand, for in other words; to be the correct answer, the structure of the passage would have to be: C. A; in other words, B.
0