Which of the following is a strategy for $Ex-situ$ conservation of animals?

In which year was the Earth Summit held?

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. Over-exploitation	$i$. Sacred groves
$B$. Ex-situ conservation	$ii$. Passenger pigeon
$C$. Alien species invasions	$iii$. Botanical garden
$D$. In-situ conservation	$iv$. Nile perch

Choose the correct answer from the options given below:

$A$ germplasm bank is developed in a botanical garden because:

In situ strategies include:
$I$. National parks
$II$. Wildlife sanctuaries
$III$. Biosphere reserves
$IV$. Sacred forests/Lakes
Choose the correct option.

Keystone species deserve protection because these