Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).  

Assertion (A): In industrial areas of England, the frequency of dark-winged moths increased after industrialisation (in 1920). 

Reason (R): During post-industrialisation period, the tree trunks became dark due to thick growth of lichens. 

In the light of the above statements, choose the most appropriate answer from the option given below. 

The given Assertion (A) is true, but  Reason (R) is false.

Assertion (A): In industrial areas of England, the frequency of dark-winged moths increased after industrialisation (in 1920). This is a well-documented observation known as industrial melanism. It refers to the increase in the frequency of dark-colored moths in industrialised areas compared to their prevalence in non-industrialised areas. The dark coloration provides better camouflage against soot-covered tree trunks.

Reason (R): During the post-industrialisation period, the tree trunks became dark due to soot. Lichesn impart white to grayish coloration tree trunks and also grow in unpolluted areas. They are good indicators of pollution. In industrial areas with high air pollution, soot and pollutants settled on tree trunks, causing them to darken. This change in tree trunk color favored the survival of dark-winged moths, as they were less visible to predators against the darkened background.