Five jumbled up sentences (labelled $1, 2, 3, 4$ and $5$), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence and key in the number of that sentence as your answer.
- The banning of Northern Lights could be considered a precursor to censoring books for "moral", world view or religious reasons.
- Attempts to ban books are attempts to silence authors who have summoned immense courage in telling their stories.
- Now the banning and challenging of books in the US has escalated to an unprecedented level.
- The widely acclaimed fantasy novel Northern Lights was banned in some parts of the US, and was the second most challenged book in the US.
- The American Library Association documented an unparalleled number of reported book challenges in $2022$, about $2,500$ unique titles.