True. Hypertrophic scars stay within the original wound margins. Therefore, the correct option is:
C. stay within original wound margins
To provide further clarification on the other options: A. Hypertrophic scars can regress over time, while keloids typically do not. B. Keloids can invade surrounding tissue, whereas hypertrophic scars do not. D. Both hypertrophic scars and keloids are related to collagen overproduction, but their behavior and characteristics are different.