The expected confidence in association rules can be defined as?

In the context of association rules, confidence is defined as a measure of how reliable a rule is. Specifically, it quantifies the likelihood that a consequent will occur given that the antecedent has occurred. Therefore, confidence can be expressed as the conditional probability of the consequent (B) occurring when the antecedent (A) is present. This means that if you have a rule of the form A → B, the confidence is essentially P(B | A), illustrating that it is about the likelihood of B given A's occurrence.

This probability provides insights into the strength of the association between the two items or events represented by A and B. It signifies how often items in the antecedent lead to items in the consequent, which is a crucial aspect in determining the usefulness and reliability of the generated rules in market basket analysis or similar applications.

The other options do not accurately capture the definition of confidence in the context of association rules, as they either focus on the probabilities of standalone events or do not properly address the relationship indicated by the rules themselves.