From the evolutionary point of view, which one of the following is closer to man ?

From an evolutionary perspective, the dolphin is the closest relative to humans among the given options. Dolphins are cetaceans, a group of water-living mammals. Like humans, they belong to the class Mammalia, characterized by features such as hair and milk production [3]. While sharks and flying fish are aquatic, they are distantly related; sharks are cartilaginous fish (Chondrichthyes) that shared a common ancestor with the lineage leading to mammals approximately 420 million years ago. Flying fish are bony fish (Actinopterygii), and tortoises are reptiles (Testudines). Although mammals and reptiles are both amniotes [3], the dolphin's classification as a fellow mammal places it in the same taxonomic class as humans, sharing a more recent common ancestor than the reptilian or fish lineages. The streamlined shape shared by sharks and dolphins is a result of convergent evolution rather than close genetic relatedness [2].

Sources

1. [3] https://en.wikipedia.org/wiki/List_of_examples_of_convergent_evolution
2. [2] https://www.nhm.ac.uk/discover/convergent-evolution.html