The idea of 'Survival of Fittest' was given by

The correct option is B Spencer
In the 1800s, after Darwin first published his book, 'On the Origin of Species', a British economist Herbert Spencer used the term "survival of the fittest" in relation to Darwin's idea of natural selection as he compared Darwin's theory to an economic principle in one of his books. This interpretation of natural selection caught on and Darwin himself even used the phrase in a later edition of 'On the Origin of Species'.