random.sort.cs

var dic = new Dictionary<string, int> { ["A"] = 0, ["B"] = 0, ["C"] = 0 };

for (int i = 0; i < 10_000; i++)
{
    var list = new List<string> { "A", "B", "C" };
    list.Sort((x, y) => new Random().Next(0, 2));

    dic[list[0]]++;
}

foreach (var kvp in dic)
{
    Console.WriteLine(kvp.Key + " -> " + kvp.Value);
}