Guys, he couldn't say the resource because if he did it would give away the civ.
Coffee doesn't give away any civ. There are a ton of places known for coffee, same with rubber.
If he said coffee we would have a thread and come up with like 5 guesses. If he said buffalo we wouldn't have 5 guesses.
Not necessarily. Brazil, Indonesia , Colombia and the Middle east (In civ with Harun and Suleiman) are the biggest exporters of coffee. Since all the others are in the game, there are not many possible options.