Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

• Peppered moth populations gradually increased in size, with dark-colored moths increasing their numbers fastest in the industrialized areas of Germany and England.
• Over a period of decades, dark-colored peppered moths came to certain areas of the Ruhr Valley and the Midlands and became the dominant forms there.
• In Germany and England, dark-colored peppered moths forced most light-colored moths out of their territories.
• While they also increased elsewhere, dark-colored peppered moths gradually became the dominant form in areas of extreme industrialization.

This is a multiple choice.