For the code snippet shown below, which of the following statements are valid?

public class TestCuriousTab
{
    public void TestSub<M> (M arg)
    {
        Console.Write(arg);
    }
}
class MyProgram
{
    static void Main(string[] args)
    {
        TestCuriousTab tab = new TestCuriousTab();
        tab.TestSub("CuriousTab ");
        tab.TestSub(4.2f);
    }
}

1. Stack
2. Tree
3. SortedDictionary
4. SortedArray

public class Generic<T>
{
    public T Field; 
    public void TestSub()
    {
        T i = Field + 1;
    }
}
class MyProgram
{
    static void Main(string[] args)
    {
        Generic<int> gen = new Generic<int>();
        gen.TestSub();
    }
}

1. Generics is a language feature.
2. We can create a generic class, however, we cannot create a generic interface in C#.NET.
3. Generics delegates are not allowed in C#.NET.
4. Generics are useful in collection classes in .NET framework.
5. None of the above

public class Generic<T>
{
    public T Field;
}
class Program
{
    static void Main(string[ ] args)
    {
        Generic<String> g = new Generic<String>();
        g.Field = "Hello";
        Console.WriteLine(g.Field);
    }
}