General terms:
* Autonomy: This is a broad term that refers to self-governance, independence, and the ability to make choices without external control.
* Self-determination: This term emphasizes the power to control your own destiny and make choices about your life.
* Agency: This term highlights the ability to act independently and be a causal agent in your own life.
More specific terms:
* Free will: This term implies a philosophical concept of choice, suggesting that we have the ability to make choices unconstrained by external factors.
* Decision-making ability: This focuses specifically on the skill and capacity to make decisions.
* Choice: This is a simple and direct term for the ability to make a selection from among options.
The best word will depend on the context of your writing or conversation.