Let $L \subseteq \{0,1\}^*$ be an arbitrary regular language accepted by a minimal $\text{DFA}$ with $k$ states. Which one of the following languages must necessarily be accepted by a minimal $\text{DFA}$ with $k$ states?
- $L-\{01\}$
- $L \cup \{01\}$
- $\{0,1\}^* – L$
- $L \cdot L$
