Because it simulates a word-of-mouth recommendation. In addition, a word of mouth promotion is important for every business as each contented customer can ox dozens of new ones your way. The word of mouth is the transient of information from an individual to individual by the oral message which could be as simple as influence somebody the period of a day.
The answer is B Spain and Portugal
This is referred to as the agricultural revolution - option d. It allowed the people to plant their own food (rather than collect) and gave them more security in life. (they could plan ahead and collect food for later).
