What is a falcon?

A falcon refers specifically to birds of the genus Falco, with the falcon species Falco peregrinus being one of the most well-known due to its speed and hunting capabilities. The distinction is important because the term "falcon" is often used to classify birds with particular traits, such as long wings and a pointed tail that are characteristic of the species within this genus.

The inclusion of “a and b but not c” as the correct answer indicates a focus on the precise definition of falcons within the context of both their specific species and their classification among birds of prey. Unlike the broader classification captured in the third option, which includes all birds used in falconry, the correct answer emphasizes the biological and taxonomic features of falcons, rather than their role or function in hunting.

This distinction matters because while there can be various birds used in falconry, not all of them are classified as falcons scientifically. The other definitions do not accurately encompass the specificity and uniqueness of what defines a falcon biologically.