On the Venn diagram, which region(s) represent the union of Set cap A and Set cap b open paren the union of cap A and cap b close paren ?

The union A ∪ B includes every region that lies in Set A, Set B, or both. In the diagram, those regions are I, II, and III; region IV is outside both sets, so it is not included. Therefore, the correct choice is “I, II, and III.”

AI-written and checked against the verified answer.