(2) It initializes the instance members of the class
...
my doubt is why not 2 is correct .....
Seems two books I checked agree with you:
From Core
Java (J2SE 5.0) , Volume I, Page 128
If you write a class with no constructors whatsoever, then a default constructor is provided for you. This default constructor sets all the instance fields to their default values. So, all numeric data contained in the instance fields would be 0, all Booleans would be false, and all object variables would be set to null.
From K&B 1.4. Page 314 when they discuss constructor chaining they also say:
5. Object constructor completes
6. Animal instance variables are given their explicit values (if any)
7. Animal constructor completes
Where did you get the question from? Do they provide any answer?