Final answer:
The best sensory organ for detecting the splashing of fish in water is the ears, which are evolved to detect sound vibrations in the environment.
Step-by-step explanation:
The question "Which sensory organ would best detect the splashing of fish in water?" pertains to the auditory system in animals. The correct answer is B. Ears. Ears are equipped to detect sound vibrations, such as the splashing of fish in water. Sensory organs for detecting stimuli like sound are crucial for survival as they allow animals to perceive their environment. For example, the lateral line is a sensory organ that runs the length of a fish's body and is used to detect vibration in the water. Similarly, the ears of animals like crocodiles are specially adapted to detect sounds and vibrations in water, thus allowing them to sense prey or the movement of other animals in their habitat.