Casey was visiting a friend in New York City on September 11, 2001, the day of the attack on the World Trade Center. To her, that day seems frozen in time. She remembers exactly where she was, what she was doing, and what she felt as the morning transpired. This vivid recollection is known as:_________
a. source misattribution.
b. a flashbulb memory.
c. a serial-position effect.
d. a frozen memory.