You have been assigned to care for a woman who was recently admitted for advanced cancer, and who reports ongoing fatigue. Her husband offers observations about his wife's fatigue. Which statement by the husband indicates the most correct understanding of his wife's fatigue?

A. "She sleeps quite a bit, so she shouldn't be as tired as she is."
B. "She's lost some weight. I know she'll feel better if she eats more."
C. "She's been in pain. If we control that maybe, she'll have more energy."
D. "She seems moody, so we need to cheer her up and make her laugh."