Identify the year of establishment for the Central Pollution Control Board $(CPCB)$ based on the following context:
$(i)$ Environment (Protection) Act: $1986$
(ii) Central Pollution Control Board $(CPCB)$: ?

Select the correct option regarding algal bloom.
$I-$ Excessive growth of planktonic algae occurs due to the presence of high amounts of nutrients in water bodies.
$II-$ Algal bloom imparts a distinct color to the water bodies.
$III-$ Algal bloom causes deterioration of water quality and fish mortality.
$IV-$ All bloom-forming algae are highly toxic to humans and animals.

Which of the following is responsible for a sound level of $150 \, dB$ or more?

As the organic matter increases in a water body,the $BOD$

$DDT$ residues are rapidly passed through the food chain causing biomagnification because $DDT$ is:

In agriculture,improper drainage of water leads to:
$I-$ The soil becomes waterlogged.
$II -$ The soil surface draws up salts from the water.
$III -$ Salts are deposited as a thin crust on the land surface.
$IV -$ Salts start accumulating around the roots of the plants.
$V -$ The increasing concentration of salts becomes favorable for crop growth.
$VI -$ It is highly beneficial for agriculture.
Which of the above statements are correct?