In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.

What was the point of the skinner box?
perform studies in conditioning and training

In 550 bc which leader began the persian empire?
Cyrus II of Persia

When's the last time the eagles went to the playoffs?

2019