I would say it is the third one down (visit the restaurants in the same trading area) because that is the only one where you gain the knowledge first hand. When you have middle men (people writing online, people who have visited the restaurant themselves, or members of the BBB) there can be a bias as they may claim the competition is better when it is not for personal gain.
Are you asking for notes and what instrument?
Can I see what the functions are? Along with the other options
