The correct answer to this open question is the following.
Although there are no options or any specific region or reference included, we can say the following.
An empire can oppress a region in that the Emperor can exert total power and control over the conquered territories and their people. When an empire conquers other nations, the Emperor orders to exploit all the raw materials and natural resources so he can get richer. Many times, subjects had to pay heavy taxation and had no liberties. They had to completely obey the Emperor's demands.
Of course, the empire would harm merchants in that it was the King or the Emperor, who benefited the most with the taxation charged on trade transactions. Or merchants had to pay a specific amount as tribute so merchants could do their work.