After the dark carbonara form of the peppered moth became prevalent in Britain, the Parliament of the UK passed emissions restrictions, reducing soot from factories. How did the new regulations affect the peppered moth population? 

A. The carbonaria (black) form became more frequent. 

B. The insularia (grey) form became more frequent.

C. The typical (white) form became more frequent.

D. The insularia (grey) form became less frequent. 

E. There was no effect on the frequency of the forms of the cornered moth.