The entire third paragraph of the story is full of evidence. The story states, "...her voice was often heard in wordy warfare with her husband" is one that would work well because often tells you that it happened frequently and warfare means fighting.
"<span>c. I sat between him and her during the sales conference" would be the only sentence that uses pronouns correctly, but it would be much more common to substitute "them" for "him and her". </span>
