?? To execute asynchronous methods inside a nested loop in .NET, we can use the async and await keywords along with the Task class.

using System;
using System.Threading.Tasks;

class Program
{
    static async Task InnerAsyncFunction(int innerData)
    {
        // Simulate an asynchronous operation
        await Task.Delay(1000);
        Console.WriteLine($"Inner data: {innerData}");
    }

    static async Task OuterAsyncFunction(int outerData)
    {
        // Simulate an asynchronous operation
        await Task.Delay(1000);
        Console.WriteLine($"Outer data: {outerData}");

        // Nested loop
        for (int innerData = 0; innerData < 3; innerData++)
        {
            // Execute the asynchronous method inside the loop
            await InnerAsyncFunction(innerData);
        }
    }

    static async Task Main()
    {
        // Outer loop
        for (int outerData = 0; outerData < 5; outerData++)
        {
            // Execute the asynchronous method inside the outer loop
            await OuterAsyncFunction(outerData);
        }
    }
}