Yes it is because no one knows and you don't expect to get the answer.
No, it is not a correct sentence.
The mistake is in the word <em />worse - you need to use the superlative (final) form of the adjective. Bad - worse - worst. So the correct answer would actually be:
Deciding to go to Barcelona was the worst decision I ever made.
Answer:
it is a convincing argument because of the several examples. It was a good idea to compare conflict with animals, which we are similar to and how they do it often with attacking, but at a grand scale.