Regular Languages

Step 1: Language Operations.
The union, intersection, and difference of languages are all regular operations. If and are accepted by finite automata and , respectively, then the languages resulting from the union, intersection, and difference of these languages will also be accepted by finite automata.

- : The union of two regular languages is regular.

- : The intersection of two regular languages is regular.

- : The difference of two regular languages is regular.

- : Similarly, the difference of two regular languages is regular.

Step 2: Conclusion.
Since all the given operations (union, intersection, and difference) result in regular languages, the correct answer is (3), as all four languages can be accepted by finite automata.