In the early $1920$s,the prickly pear cactus introduced into Australia caused havoc by spreading rapidly into millions of hectares of rangeland. Finally,how was it controlled?

Species $A$ $(-)$ and Species $B$ $(O)$ show which of the following interactions?

Choose the correct option for population interaction.

In the following,which interaction is indicated by $+/-$?

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

Column $-I$	Column $-II$
$(a)$ Predation	$(i) \ (-, 0)$
$(b)$ Commensalism	$(ii) \ (+, -)$
$(c)$ Mutualism	$(iii) \ (+, 0)$
$(d)$ Amensalism	$(iv) \ (+, +)$

Even a plant species,which makes its own food,cannot survive alone; it needs soil microbes to breakdown the $A$ matter in soil and return the $B$ nutrients for absorption. And then,how will the plant manage pollination without an animal agent? It is obvious that in nature,animals,plants and microbes cannot live in $C$ but interact in various ways to form a biological community. Choose the correct option for $A, B$ and $C$.