The monitoring stations,established by $NEERI$,have reported that Kolkata and New Delhi have highest . . . . . . and . . . . . . in air respectively.

Consider the following statements:
$I.$ Reforestation is the process of restoring a forest that once existed but was removed at some point of time in the past.
$II.$ Reforestation may occur naturally in a deforested area.
$III.$ $A$ tree plantation movement or Van Mahotsava is being carried out in India since $1982$.
Which of the statements given above are correct?

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Environment Act	$(1)$ $1974$
$(b)$ The Air Act	$(2)$ $1987$
$(c)$ The Water Act	$(3)$ $1986$
$(d)$ Amendment in The Air Act	$(4)$ $1981$

Increase in concentration of a toxicant at successive trophic levels is called

Consider the following statements about Ramesh Chandra Dagar's work in the field of organic farming:
$I.$ Ramesh Chandra Dagar's work includes bee-keeping,dairy management,water harvesting,composting,and agriculture in a chain of processes.
$II.$ In this process,there is no need to use chemical fertilisers for crops as cattle excreta is used as manure.
$III.$ Crop waste is used for making compost,which is used as natural fertilizer.
$IV.$ Compost generates natural gas,which is used for the energy needs of the farm.
Which of the statements given above are correct?

Identify the correct statement regarding Eutrophication.