(a) "In stock markets, the investors are in a zero-sum game." Is this statement true or false? Explain your answer. (b) "In the area of machine learning, reinforcement learning is one base paradigm. It aims to find the action which leads to the maximum reward or drive to the optimal outcome." According to this statement, can we interpret the problem of reinforcement learning directly as a game theory problem of finding the Nash equilibria? Explain your answer.