What is a beta cutoff in the alpha$-$beta pruning algorithm?

Select one:

A scenario where a minimiser node stops evaluating further because a worse value is already assured elsewhere.

A situation where the beta value is reset to positive infinity.

A scenario where a maximiser node stops evaluating further because a worse value is already assured elsewhere.

A method to decrease the search depth dynamically.

A reduction in the alpha value at a minimiser node.