Answer: B. Other markets in the U.S. may still trade XYZ stock
Explanation:
A Non-regulatory trading halt is one that occurs due to a 7% drop in the S&P 500 Index. When this happens, all stock markets in the US are to halt trade.
This is very theoretical however because in reality, when this happens, traders can simply trade on other markets in the US including regional exchanges, Third Market Makers and Electronic Communication Networks.
