MergeSort in c# array error

Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at sort.sort.MergeSort(Int32[] array) in c:\Users\Muhammad Rizwan\Documents\Projects\sort\sort\Main.cs:line 44
   at sort.sort.Main() in c:\Users\Muhammad Rizwan\Documents\Projects\sort\sort\Main.cs:line 66
Press any key to continue . . .

using System;
using System.Collections.Generic;
using System.Linq;

namespace sort
{
	class sort{
		public static int[] MergeSort(int[] array)
		{	
			if (array.Length == 2) {
				int t = array[0];
				if(array[0] > array[1]){
					array[0] = array[1];
					array[1] = t;
				}
			}
			else if(array.Length > 2){

				int m = array.Length/2;	

				int[] A, B;
				A = new int[m];
				B = new int[(array.Length-m)];

				for(int i =0; i <= m-1;i++){
					A[i] = array[i];
				}
				for(int i = m ; i <= array.Length-1;i++){
					B[i-m] = array[i];
				}				
				
				int r =0;
				int q =0;
				

				for(int k = 0; k <= array.Length; k++){
					if(A[r] <= B[q]){  //line 44
						array[k] = A[r];
						r++;					
					}
					else{
						array[k] = B[q];
						q++;	
					}
				}

			}			
			return array;
		}	

		static void Main(){
			int[] array = {5, 2, 6, 4, 7, 10, 1, 9, 3, 8};

			array = MergeSort (array);
		        for (int i = 0; i <= array.Length; i++) {
				Console.WriteLine(array[i].ToString());
			}
		}
		
	}
}