Who proposed Survival of fittest" ?

Who proposed ''survival of the fittest'' theory?

The phrase ‘Survival of the fittest’ as a way of describing the mechanism of natural selection was coined by "__________" .

The phrase 'Survival of the fittest' was first used by Herbert Spencer. The same phrase was used by Darwin as

Survival of Fittest was used by

When we say "survival of fittest" does it mean that (a) Those which are fit only survive or (b) Those that survive called fit.

Identify the correlation between the first two words and suggest the suitable words in the fourth place: Survival of fittest: Darwin::Acquired characters:………….