Questions 23 and 24 are based on the following. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news. According to a police officer, the protest was triggered______

A．for a local police commander ordered Ms men to open fire on them
B．for a nearby petrochemical plant had dismissed some young employers
C．for protesters demanded to find a job in the local oil-related factories
D．for the police had killed a young man from the neighborhood