What term describes the actions exhibited by a living organism?

The term that best describes the actions exhibited by a living organism is behavior. Behavior encompasses all observable actions, reactions, or activities that an organism engages in, whether in response to internal stimuli (like hunger or excitement) or external stimuli (like environmental changes or social interactions). This broad definition includes everything from simple reflexes to complex social interactions and learned skills.

Understanding behavior is crucial in various fields like psychology, biology, and applied behavior analysis, as it provides insights into how organisms interact with their environment and each other. In contrast, the other options might represent specific aspects or contexts of actions but do not capture the full spectrum of what behavior entails. For instance, reactions generally refer to specific responses to stimuli, conduct often implies behavior that is governed by social norms, and performance might emphasize execution in particular tasks rather than all-encompassing actions.