Solution

1. For object \((c,d)\), the identity morphism is \((id_c,id_d)\)

2. The operation was defined in terms of function composition which is associative.

3. It is isomorphic to just 2

4. The underlying set is the cartesian product, and \((a,b)\leq(a',b')\) iff \(a \leq a' \land b \leq b'\)