problem in returning a matrix(2d array) to main function

in my program, i've taken the input from user, passed the 2 input matrices to the addtn function which performs addition,
but the function is not returning the correct values to main,it is actually returning garbage values
Mainly, i want to learn how to return a 2d array to the main module

This is main module

Code:

#include<stdio.h>
#include<conio.h>
void input(int (*in)[3]);
int *addtn(int (*x)[3],int (*y)[3]);
void main()
{
int mat1[3][3],mat2[3][3],choice;
int i,j,(*res)[3];
clrscr();

printf("\nEnter the elements of first matrix:\n");
input(mat1);
printf("\nEnter the elements of second matrix:\n");
input(mat2);

do
	{
	clrscr();
	printf("\t\t\t 1) ADDITION\n");
	printf("\t\t\t 2) EXIT\n\n\n");
	printf("\n\nEnter Your choice: ");
	scanf("%d",&choice);
		switch(choice)
		{
		case 1:
			res=addtn(mat1,mat2);
			for(i=0;i<3;i++)
			{
				for(j=0;j<3;j++)
				{
				printf("%d\t",*(*(res+i)+j));
				}
			}
			getch();
			break;
		case 2:
			exit(1);
		default :
			printf("Not in the list of choices. Enter from the list only!");
		}

}while(1);
}

This is for input

Code:

//********************************INPUT**************************
void input(int (*in)[3])
{
int i,j;
for(i=0;i<3;i++)
{
	for(j=0;j<3;j++)
	{
		printf("\nEnter the Element of row,%d and col,%d: ",i+1,j+1);
		scanf("%d",(*(in+i)+j));
	}
}
getch();
clrscr();
}

For addition, the problem area, which is not returning correctly

Code:

int *addtn(int (*x)[3],int (*y)[3])
{
int i,j,c[3][3];
for(i=0;i<3;i++)
	for(j=0;j<3;j++)
		c[i][j]=0;


for(i=0;i<3;i++)
{
	for(j=0;j<3;j++)
	{
		c[i][j]= *(*(x+i)+j)+ *(*(y+i)+j);    //performing addition here
	}
}
getch();
clrscr();
return(c);             //returning here
}

 

Can you please give me the warning/error message if you get?
If no such, have you tried to print that array?