Answer:
B. Then.
Explanation:
The word that exemplifies the sequence between the two sentences would be "Then" as the latter sentence is following the action of the first which could be complemented by adverb 'then'. Then is usually employed to express a sense of time or leads the forthcoming action. Thus, after the revision, the sentence reads as follows:
I developed a research question and conducted my research, then I wrote the results in a report.
