问题如下：
In contrast to gambling, derivatives speculation:
选项：
A.has a positive public image.
B.is a form of financial risk taking.
C.benefits the financial markets and thus society.
解释：
C is correct. Derivatives trading brings extensive benefits to financial markets (low costs, low capital requirements, ease of going short, etc.) and thus benefits society as a whole. Gambling, on the other hand, typically benefits only a limited number of participants. A is incorrect because the general image of speculators is not a good one. Speculators are often thought to be short- term traders who attempt to exploit temporary inefficiencies, caring little about long- term fundamental values. B is incorrect because speculation and gambling are both forms of financial risk taking.
这道题的a和b选项不懂，求解析，谢谢！
