According to Darwin, the organic evolution is due to
Competition within closely related species
Reduced feeding efficiency in one species, due to the presence of interfering species
The correct option is B Interspecific competition
Interspecific competition is the competition among the different species for food shelter causes organic evolution, given by Darwin. Whereas intraspecific competition is the competition among the member of the same species. If there will be competition within the closely related species then evolution does not occur. The reduced feeding efficiency in one species due to the presence of interfering species is because of the struggle for existence.