Which of the following is an element? !The Full Question entailed The full question is in the picture. Which of the following is an element? I feel that choice 1 is correct and choice 2 is wrong. It leaves me with the remaining two choices. I don't quite understand how the union of sets in here work. Can someone explain it to me the outcome of the union of the two sets? Answer can be more than 1 or none at all

Given any set $A$, the set $A\cup \emptyset=A$. (Think of starting with $A$ and then adding nothing to it). Thus, your set in question is $\\{\emptyset,\\{\emptyset\\}\\}$. This set has two elements: $\emptyset$ and $\\{\emptyset\\}$.