What type of human population is represented by the given age pyramid?

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(a)$ Mutualism	$(i)$ Potent force of organic evolution
$(b)$ Orchid	$(ii)$ Negative interaction
$(c)$ Parasitism	$(iii)$ Beneficial interaction
$(d)$ Competition	$(iv)$ No harm to the host

$X$ - In deep-sea hydrothermal vents,the average temperature is between $25^{\circ}C$ to $30^{\circ}C$.
$Y$ - Reptiles and amphibians are eurythermal.

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(a)$ Allen's Rule	$(i)$ Kangaroo rat
$(b)$ Physiological adaptation	$(ii)$ Desert lizard
$(c)$ Behavioural adaptation	$(iii)$ Marine fish at depth
$(d)$ Biochemical adaptation	$(iv)$ Polar seal

Choose the correct answer from the options given below.

Match the following columns regarding physiological adaptations in organisms:

Column-$I$	Column-$II$
$(a)$ Diapause	$(i)$ Inactive stage during summer
$(b)$ Hibernation	$(ii)$ Inactive stage during winter
$(c)$ Dormancy	$(iii)$ Temporary suspension of development
$(d)$ Aestivation	$(iv)$ Reduced metabolic state during unfavorable conditions

Countries with high population growth rates have taken measures to reduce them. The figure below shows the age pyramids of populations. Which of the following is a correct interpretation for their status after $20$ years?