As with all multiple choice questions, if you have a textbook, course readings, or notes from an instructor that need to be followed, I would stick with those before venturing out anywhere else. Options A and B are not logical because Iran-Contra took place in the President's second term and his family members were not directly involved. There is little to indicate that the President and his staff needed to secure needed arms sales, especially to a nation like Iran that was under an arms embargo. I would say that one of the hopes of those who facilitated the transactions in the Iran-Contra Affair hoped for letter D in obtaining the release of American Hostages in Lebanon. It was believed that Iran would be able to be of some influence in the release of hostages that were held in Lebanon. At the same time, another hope of the engagement was to help fund the Contra rebellion in Nicaragua. It should be noted that nothing was really proven in suggesting that Reagan had authorized the affair. The Tower Commission criticized Reagan for promoting a climate that was not under his control, but could not conclude that Reagan had direct knowledge of violating any principle that precluded with negotiating with terrorists.
The best answer to this question is D. None of the others is really a good answer.
First of all, A cannot be the case. Reagan won his second term in the election of 1984. Therefore, it was not possible for his actions in '85 to be based on the desire for reelection. B is not possible because none of Reagan's family members were in the military or held hostage or anything like that. However, there was a major issue during those years with American and other Western people being held hostage in Lebanon. It was in order to help secure the release of these hostages that Reagan was willing to negotiate with Hezbollah.