please kindly help solve this Java questions. God bless! Thank you!

Look at the following code. Which line will cause a compiler error? Line 1 public class ClassA Line 2 {Line 3 public ClassA () {} Line 4 public int method1 (int a) {} Line 5 public final int method2(double b) {} Line 6} Line 7 public ClassB extends ClassA Line 8 {Line 9 public ClassB () {} Line 10 public int method 1 (int b) {} Line 11 public int method2 (double c) {} Line 12} What is wrong with the following code? public class ClassB extends ClassA {public Class B () {int init = 10; super(40);}}