Jan Gimsa, Robert Sleigh, and Ulrike Gimsa have hypothesized that the sail- like structure running down the back of the dinosaur Spinosaurus aegyptiacus improved the animal's success in underwater pursuits of prey species capable of making quick, evasive movements. To evaluate their hypothesis, a second team of researchers constructed two battery-powered mechanical models of S. aegyptiacus, one with a sail and one without, and subjected the models to a series of identical tests in a water-filled tank. Which finding from the model tests, if true, would most strongly support Gimsa and colleagues' hypothesis? Choose 1 answer: © The model with a sail took significantly longer to travel a specified distance while submerged than the model without a sail did. (B) The model with a sail displaced significantly more water while submerged than the model without a sail did. (C) The model with a sail had significantly less battery power remaining after completing the tests than the model without a sail did. (D) The model with a sail took significantly less time to complete a sharp turn while submerged than the model without a sail did.

The hypothesis by Jan Gimsa, Robert Sleigh, and Ulrike Gimsa suggests that the sail-like structure on **Spinosaurus aegyptiacus** enhanced its ability to pursue underwater prey, particularly those capable of making quick and evasive maneuvers. To support this hypothesis, evidence should demonstrate that the sail contributed positively to the dinosaur's maneuverability or speed during underwater movements. Let's evaluate the options: - **Option A:** If the model with a sail took longer to travel a specified distance, it would indicate a hindrance rather than an advantage, contradicting the hypothesis. - **Option B:** Displacing more water could imply increased drag, which might not necessarily support enhanced pursuit capabilities. - **Option C:** Using more battery power suggests that the sail may have added resistance or required more energy, which doesn't directly support improved hunting efficiency. - **Option D:** A model with a sail completing sharp turns more quickly directly indicates enhanced maneuverability. This would allow the dinosaur to make swift changes in direction when chasing evasive prey, strongly supporting the hypothesis. **Answer:** (D) The model with a sail took significantly less time to complete a sharp turn while submerged than the model without a sail did.