Q1:

public class MyOuter 
{
    public static class MyInner 
    {
        public static void foo() { }
    }
}

which statement, if placed in a class other than MyOuter or MyInner, instantiates an instance of the nested class?

ANS:A - MyOuter.MyInner m = new MyOuter.MyInner();

MyInner is a static nested class, so it must be instantiated using the fully-scoped name of MyOuter.MyInner. Option B is incorrect because it doesn't use the enclosing name in the new. Option C is incorrect because it uses incorrect syntax. When you instantiate a nested class by invoking new on an instance of the enclosing class, you do not use the enclosing name. The difference between Option A and C is that Option C is calling new on an instance of the enclosing class rather than just new by itself. Option D is incorrect because it doesn't use the enclosing class name in the variable declaration.