Which of the following best describes a mixed strategy?

A mixed strategy is defined as one that involves using a combination of different strategies, where the decision-maker assigns probabilities to each possible action and makes choices based on these probabilities. This approach is particularly relevant in game theory, where players may want to keep their opponents uncertain about their next move to optimize their outcomes.

In this context, a mixed strategy stands in contrast to a deterministic method, which would rely on a fixed choice without randomness. The element of randomness in a mixed strategy allows for flexibility and variability, reducing predictability and providing a strategic advantage.

While other options such as utilizing historical data and continuous monitoring of an opponent's strategy may have their own relevance in decision-making contexts, they do not encapsulate the essence of a mixed strategy as the correct answer does. The core characteristic of a mixed strategy lies in its probabilistic approach to decision-making rather than reliance on past data or tracking opponent movement.