Heisenberg's Uncertainty Principle is a fundamental concept in quantum mechanics that states there is a limit to how precisely we can simultaneously know certain pairs of properties of a particle, such as position and momentum. This principle introduces an element of fundamental unpredictability or indeterminacy in the behavior of particles at the quantum level.
Step 2: Relating the Principle to Philosophical Concepts
In the context of philosophical discussions on freewill and determinism, Heisenberg's Uncertainty Principle is often associated with indeterminism. Indeterminism is the idea that not all events are determined by preceding causes and that there is an element of randomness or unpredictability in the universe. This aligns with the inherent unpredictability introduced by the Uncertainty Principle.
Final Answer
The answer is \(\boxed{\text{B}}\) (indeterminism).