Spokesperson: Contrary to what some have claimed, our group' s "Clean City" campaign has been a rousing success. After all, the amount of trash on the city' s streets today is significantly lower than when the campaign began. Which one of the following is an assumption required by the spokesperson's argument?
A: Those who claim that the campaign has not been a rousing success are unaware of the degree of the decline in the amount of trash since the campaign began.
B: The amount of trash on the city's streets was not declining at the same rate or faster before the campaign began than it did during the campaign.
C: The amount of trash on the city's streets has declined steadily throughout the course of the campaign.
D: The campaign has been more successful in reducing the amount of trash on the city's streets than has any other campaign in the past.
Choose A, B, C or D as your solution.
B