What is the result of ∅∪{a,b}\emptyset \cup \{a, b\}∅∪{a,b}?
{a,b}\{a, b\}{a,b}
{a,b,∅}\{a, b, \emptyset\}{a,b,∅}
∅\emptyset∅
{0,a,b}\{0, a, b\}{0,a,b}