The correct answer is option 1, Bat. When considering organic evolution, it is important to note that there is no inherent hierarchy or level of advancement among species. However, in this particular question, the term "advanced" is used to describe the species that has undergone significant adaptations and possesses unique attributes compared to the others.

In this case, bats are considered more advanced than the other three options (pigeon, ostrich, and vulture) because they have developed the ability to fly. Flight is a complex and specialized adaptation that requires adaptations in their wings, muscles, and sensory systems. Bats are the only mammals that have achieved true flight, making them unique and advanced in terms of their evolutionary adaptations.

It is important to note that this classification of "advanced" is based on specific criteria and should not be used to judge the overall value or importance of a species. Each animal has evolved to fit into its specific ecological niche, and all species play a vital role in their respective ecosystems. So while bats may be more advanced in terms of flight adaptation, each of the other species has its own impressive evolutionary features that make them well-suited to their environments.