Answer:
The correct answer is letter "B": the weak-form EMH.
Step-by-step explanation:
The weak-form efficiency is one of the three Efficient Market Hypothesis (EMH) that establishes that past stock prices movement does not help "predicting" future stock prices. In that sense, Joe held his shares until the price returned to the point where he purchased them to break even. If a trading pattern is created based on this, it will imply that the stock prices would repeat a movement that will lead them to return to a specific price level, so past stock prices movement will be useful to "predict" future price movement, which is the opposite that states the weak-form EMH.