An association rule is represented as which of the following?

An association rule is typically expressed in the format of an implication between two item sets, showing how the occurrence of one set of items can lead to the occurrence of another set of items. The notation (item set A) => (item set B) signifies that if item set A is present in a transaction, there is a certain probability that item set B will also be present in that transaction.

This format is fundamental in association rule mining, a technique commonly used in market basket analysis, where it helps identify relationships between items purchased together. The rule captures the directional relationship and provides insights into customer purchasing patterns, making it a vital tool for various business applications.

The other options provided also take on the same structure but represent different item sets. However, the first choice aligns with the standard representation of association rules and illustrates the concept of how one item set influences another in a pragmatic scenario.