Because that is when the DOI was signed, it was passed later on I believe
where is the map you are referring to?
The correct answer to this question is this one: "D. having a rock concert in a public park in Japan"
The first three have a key point: requiring or changing by force. The last one just says having a rock concert in a public park in Japan. It's not forced, but voluntary whereas the first three are in a sense, forced.
