问题如下：
The key assumption of technical analysis is:
选项：
A. The efficient market hypothesis does not hold.
B. Market trends and patterns can not reflect investors’ behaviors.
C. Market trends and pattern will not repeat and are difficult to forecast.
解释：
A is correct.
A key assumption of technical analysis is that market prices reflect both rational and irrational investor behavior, which implies that market is not efficient. Investors tend to behave similarly in similar circumstances. Thus, the market trends and patterns may repeat themselves and be predictable in a way.
