The Marriott is a popular place for foreigners to stay and a prominent enterprise in the city, despite a wave of violence the country suffers. The hotel had been victim of another attack in January 2007 where a security guard was killed and several people injured after the guard blocked a bomber from getting at the hotel, forcing him to detonate his explosives where he was.
Can we infer the following?
The security guard tried to warn the hotel

OPT:
+ Yes.
+ It's impossible to say.
+ No.
The answer is:
It's impossible to say