Question

If A = {positive even integers} and B = {positive odd integers}, what is A B? {positive integers}
{integers}
{0}
{ }

Answer 1

can you be clearer with the question?
did you mean -> what is A multiplied by B?

Answer 2

If A = {positive even integers} and B = {positive odd integers}, what is A ⋃ B? {positive integers}
{integers}
{0}
{ }