Find smallest interval between 2 entity in one List

Find smallest interval between 2 entity in one List<int>

 using System;

using System.Linq;

using System.IO;

using System.Text;

using System.Collections;

using System.Collections.Generic;

using System.Text.Json;

using System.Text.Json.Serialization;

using System.Runtime.Serialization;

public class Solution {

    public static int FindSmallestInterval(List<int> numbers) {

        // Write your code here

        if(numbers.Count < 2 || numbers.Count >100000){

            throw new ArgumentException("invalid input");

        }

        

        var arrayNumbers = numbers.ToArray();

        Array.Sort(arrayNumbers);

        int toReturn = int.MaxValue;

        for (int i = 1; i < arrayNumbers.Length; i++)

        {

            toReturn = Math.Min(toReturn, arrayNumbers[i] - arrayNumbers[i - 1]);

        }

        return toReturn;

    }