Sachin,
There is no standard answer to your question. Let me ask you another question: What is the first thing you need to do if you are over budget? Or... what is the first thing you need to do if you notice that a deliverable is behind schedule? The answer is: "It depends".
It is the same with questions about ethics. You have to review the question, analyze the available answers and then make your selection. If you answered incorrectly, then all you can do is to read the explanation and learn from it.
It is unfortunate that I cannot give you better guidance, but when it comes to ethics the approach is not always black or white. There are many shades in between and it depends very much on the situation.