SCJP - 27 -Given Example

What is the result?
A. 2
B. 4
C. An exception is thrown at runtime
D. Compilation fails due to an error on line 4.
E. Compilation fails due to an error on line 5.
F. Compilation fails due to an error on line 6.
G. Compilation fails due to an error on line 7.

Answer:

C is correct. A ClassCastException is thrown at line 7 because o1 refers to an int[][]
not an int[]. If line 7 was removed, the output would be 4.

A, B, D, E, F, and G are incorrect based on the above. (Objective 1.3)
==

class Dims {
public static void main(String[] args) {
int[][] a = {{1,2,}, {3,4}};
int[] b = (int[]) a[1];
Object o1 = a;
int[][] a2 = (int[][]) o1;
int[] b2 = (int[]) o1;
System.out.println(b[1]);
} }