Which of the following is equivalent to the Cartesian product A×BA \times BA×B if A={1,2}A = \{1, 2\}A={1,2} and B={a,b}B = \{a, b\}B={a,b}?
{(1,a),(1,b),(2,a),(2,b)}\{(1, a), (1, b), (2, a), (2, b)\}{(1,a),(1,b),(2,a),(2,b)}
{(1,1),(2,2),(a,a),(b,b)}\{(1, 1), (2, 2), (a, a), (b, b)\}{(1,1),(2,2),(a,a),(b,b)}
{1,2,a,b}\{1, 2, a, b\}{1,2,a,b}
{(1,2),(a,b)}\{(1, 2), (a, b)\}{(1,2),(a,b)}