The correct answer is option 2, Dolphin. From an evolutionary perspective, organisms can be considered more advanced based on various factors such as the complexity of their physical and cognitive capabilities, their adaptability to different environments, and their evolutionary lineage.

In this question, the dolphin is considered more advanced than the other three organisms (crocodile, shark, and tortoise) because of its relatively higher level of intelligence and complex social behaviors. Dolphins belong to the mammalian class, which is generally considered more advanced in terms of evolutionary progression compared to reptiles such as crocodiles, sharks, and tortoises.

Dolphins are known for their highly developed brains, sophisticated communication abilities, and problem-solving skills. They also exhibit complex social structures and cooperative behaviors. These characteristics indicate a higher level of cognitive and behavioral complexity, making dolphins more advanced from an evolutionary standpoint.

While crocodiles, sharks, and tortoises have their own unique adaptations that have allowed them to survive and thrive in their respective habitats, they do not possess the same level of physical and cognitive complexity as dolphins, hence they are considered less advanced in comparison.

Therefore, the dolphin is considered the most advanced organism among the options provided.