LargestOfFour.cs

void Main()
{
	int[][] arguments = new int[][] 
						{ 
							new int[] {4,5,1,3}, 
							new int[] {13,27,18,26}, 
						   	new int[] {32,35,37,39}, 
							new int[] {1000, 1001, 857,1} 
						};
											
	int[] result = LargestOfFour( arguments );
	
	Console.WriteLine(result);
}

// Define other methods and classes here
int[] LargestOfFour(int[][] lists) 
{
	int[] largestValues = new int[ lists.Length ];
	
	for(int i = 0; i < lists.Length; i++) 
	{
		int[] currentList = lists[i];
		
		int currentLargest = GetLargestValue( currentList );
		
		largestValues[i] = currentLargest;
	}
	
	return largestValues;
}

int GetLargestValue(int[] list) 
{
	int largestValue = int.MinValue;
	
	for(int i = 0; i < list.Length; i++) 
	{
		if(list[i] > largestValue) 
		{
			largestValue = list[i];
		}
	}
	
	return largestValue;
}