Which one of the following statements is TRUE?

1. Every time the prime minister of Canada makes an announcement, the stock price of the Royal Bank of Canada changes.
2. The stock price of the Royal Bank of Canada does not respond to announcements by the prime minister of Canada because the stock market is efficient.
3. The stock price of the Royal Bank of Canada responds to an announcement by the prime minister of Canada only when the announcement deviates from the expectations of the investors.
4. All of the above are true.
5. None of the above are true.