The correct answer is D.
The cost has risen 1,000$ (comparting the 1500$ he had paid, with the 2500$ his friend has offered for the vacation, 1000$ is the amount he would miss if rejecting the offer plus the value of the activity he would do instead of the skiing vacation).
This cost rise represents the concept of opportunity cost. It is referred, when making a decision, to the value that is missed when rejecting the alternative option.
Identifying conflicting goals is part of conflict analysis, also called conflict assessment which is an initial step in the conflict resolution process. Identifying conflicting goal seeks to gain a deeper appreciation of the issues causing the conflict which contributes to coming up with resolutions
Should Elton's deception be discovered, he could be charged with Insurance Fraud, for breaking the conditions and the terms of the car insurance contract he agreed upon with the company. The fact that he sought opportunity for profit, by reporting falsely, he broke the Principle of Utmost Good Faith, which requires the complete information from the person getting the insurance.