You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: LANDMARKS
Clue: In the 1879 Mathew Brady photo seen here, this structure was about 150 feet tall
washington monument

Category: ROMAN EMPERORS
Clue: In 59 A.D. Agrippina wrote to this man, her son, "Tell me why I should plot against your life?"--she was killed anyway
nero

Category: PSYCHOLOGY
Clue: In 1973 4 bank employees held hostage in this city ended up feeling grateful to their captors
stockholm