Which of the following is true? Assume that the sets are not meant to be multisets, so the

axiom of extension applies.

The sets $\{1,0,1,0,2\}$ and $\{4,3,5,5,4,3\}$ have the same number of elements.

The set $\{\frac{O}{,}1\}($where $\frac{O}{?}$ is the emptyset$)$ contains only $1$ element.

The set $\frac{O}{}\{1,2\}$ has fewer elements than the power set $P(\{1\}).$

The set $\{,,,\}$ contains $4$ elements.