Trouble with setState() not being defined for the type 'Options' in Flutter

I was trying to add a dropdown menu for a project that I’m currently making and I ran into an issue with my code. I was following a tutorial on YouTube to build a simple one, but I’ve run into the following error; "The method ‘setState’ isn’t defined for the type ‘Options’.:21"

Here is the code:

import 'package:flutter/material.dart';

class Options extends StatelessWidget
{
  const Options({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context)
  {
    List<String> ratings = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10'];
    String? selectedRating = '1';
    return Container(
      child: DropdownButton<String>(
        value: selectedRating,
        items: ratings
            .map((item) => DropdownMenuItem<String>(
              value: item,
              child: Text(item, style: const TextStyle(fontSize: 24)),
        ))
            .toList(),
            onChanged: (item) => setState(() => selectedRating = item),
      ),
    );
  }
}

I was looking into the documentation on Flutter’s website, and I couldn’t find something relevant to the error I’m currently facing.