Critical Reasoning (CR) | Re: In the years since the city of London imposed strict

In the years since the city of London imposed strict air-pollution regulations on local industry, the number of bird species seen in and around London has increased dramatically. Similar air-pollution rules should be imposed in other major cities.

Each of the following is an assumption made in the argument above EXCEPT:

(A) In most major cities, air-pollution problems are caused almost entirely by local industry.
(B) Air-pollution regulations on industry have a significant impact on the quality