Display is a phenomenon which occurs when an animal is

The phenomenon of display in animals refers to a specific behavior that an animal exhibits to communicate with others of its own species. It is often a visual display, such as a series of postures or movements, that conveys information about the animal's readiness to mate, social status, or intention to defend its territory. Display can also involve vocalizations or the release of pheromones. Therefore, out of the options given, the correct one would be "ready for mating" as display is a behavior that animals engage in to attract potential mates and signal their readiness to mate. This behavior is often seen in birds during their mating season where they perform elaborate displays of feathers and calls to attract a mate.