Final answer:
American options are more complex than European options because they can be exercised anytime before expiration, making their valuation more complex. In foreign policy, complexity arises from the unpredictability of the international environment. In games, decisions vary with changing situations during gameplay.
Step-by-step explanation:
Regarding the complexity of American options compared to European options, the correct answer is B. More complex. American options can be exercised at any time up to their expiration date, providing the option holder with greater flexibility and the potential for more strategic decision-making compared to European options, which can only be exercised upon expiration. This flexibility can result in a more complex valuation process for American options, since multiple exercise opportunities must be taken into account.
Regarding foreign policy issues, the answer is C. The international environment is unpredictable. Foreign policy issues often involve multiple countries with their own interests, comparing to domestic policies which are confined within a single nation's borders. This multiplicity of actors and interests contributes to the complexity and unpredictability of international affairs.
In the context of games, answer A. as the situation varies is the one that makes the most sense. Decisions in games are often dependent on the changing situations within the game rather than external factors such as the time of the year, the location, or the day of the week.