1. class Dog { } 2. class Beagle extends Dog { } 3. 4. class Kennel { 5. public static void main(String [] arfs) { 6. Beagle b1 = new Beagle(); 7. Dog dog1 = new Dog(); 8. Dog dog2 = b1; 9. // insert code here 10. } 11. } Which, inserted at line 9, will compile? (Choose all that apply.)

To determine which statements will compile, let's analyze each option:

A. Beagle b2 = (Beagle) dog1; This statement will not compile because it is trying to cast a Dog object (dog1) to a Beagle object. However, dog1 is not an instance of Beagle, so the cast is not valid.

B. Runtime Exception This option is not applicable as it is not a valid code statement.

C. Beagle b4 = dog2; This statement will not compile because it is trying to assign a Dog object (dog2) to a Beagle variable (b4). In Java, you cannot assign an object of a superclass to a variable of its subclass type without explicit casting.

D. None of the above statements will compile This option is incorrect because statement A will compile.

Therefore, the correct answer is A) Beagle b2 = (Beagle) dog1.