Let $Y = \{1, 2, 3, 4, 5\}, A = \{1, 2\}, B = \{3, 4, 5\}$ and $\phi$ denote the null set. If $A × B$ denotes the cartesian product of sets A and B, then $(Y × A)∩(Y × B)$ is

$Y$ $A$ $B$ $\phi$

$\phi$

We have, $(Y × A)∩(Y × B)=Y ×(A∩B)=Y ×\phi=\phi$.