The Cartesian product $A \times B$ is defined as—

• a$\{(x, y) : x \in A$ and $y \in B\}$
• b$\{(x, y) : x \in A$ or $y \in B\}$
• c$\{x : x \in A \cap B\}$
• d$\{x : x \in A \cup B\}$