Which of the following characteristics of an ecosystem is naturally provided to human society?

Which of the following statements regarding food chains are considered correct?
$(1)$ Removal of $80\%$ of tigers from an area results in greatly increased growth of vegetation.
$(2)$ Removal of most carnivores results in an increased population of deer.
$(3)$ The length of food chains is generally limited to $3-4$ trophic levels due to energy loss.
$(4)$ The length of food chains can vary from $2$ to $8$ trophic levels.

Identify the stage of hydrarch succession shown in the figure.

Match the following:

Trophic levels	Examples
$A$. First	$a$. Man
$B$. Second	$b$. Wolf
$C$. Third	$c$. Cow
$D$. Fourth	$d$. Phytoplankton

Select the incorrect match.
$I.$ Sedimentary nutrient cycle-Nitrogen cycle
$II.$ Pioneer species-Lichens
$III.$ Secondary succession-Burned forests
$IV.$ Pyramid of biomass in sea-Upright

How much carbon is dissolved in the oceans (in $; \%$)?