'Survival of the fittest' was used by

The correct option is D Herbert Spencer
Herbert Spencer, a sociologist, coined the phrase “survival of fittest” to explain the tendency of human society to change by itself as strongest and fittest survive while weak abolish by themselves. Darwin applied the phrase “survival of fittest” to refer to the unequal ability of individuals to survive and reproduce based on suitability of their inherited characters to prevailing environmental conditions. Lamarck viewed the inheritance of acquired characters as the basis of evolution. Hugo de Vries visualized discontinuous variations, i.e. mutations, as the basis of evolution. Thus, the correct answer is option D.