In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. This characteristic feature of nature is known as

Given below are two statements.
Statement $I$: Under unlimited resource conditions,every species is capable of growing exponentially.
Statement $II$: $A$ population growing in a habitat with limited resources initially shows a very slow rate of growth.
In the light of the above statements,choose the correct option.

$I.$ Populations evolve to maximize their reproductive fitness,also called Darwinian reproductive fitness (higher $r$ value),in the habitat in which they live.
$II.$ The population growth rate $r$ is inversely related to generation time.
$III.$ The housefly,which has a short life span and produces a large number of eggs,could be considered as a '$K$' selected species.
$IV.$ Under a particular set of selection pressures,organisms evolve towards the most efficient reproductive strategies.
$V.$ Life history traits of organisms have evolved in relation to the constraints imposed by biotic and abiotic factors in their habitat.
Select the combination of correct statements.

Exponential population growth is represented by

Any species growing $A$ under unlimited resource conditions can reach enormous population densities in a short time. Darwin showed how even $B$ growing animal like elephant could reach enormous numbers in absence of check and that characteristics of organism is called $C$. Choose the correct option for $A, B$ or $C$ respectively.

What does the given figure indicate?