不是说有效市场中不允许套利么？有套利机会那不就不有效了吗

问题如下：

With respect to efficient market theory, when a market allows short selling, the efficiency of the market is most likely to:

选项：

A.

increase

B.

decrease

C.

remain the same

解释：

According to the theory, reducing the restrictions on trading will allow for more arbitrage trading, thereby promoting more efficient pricing. Although regulators argue that short selling exaggerates downward price movements, empirical research indicates that short selling is helpful in price discovery