Why does no predator become perfectly efficient at acquiring prey?

Which of the following represents the correct pair of organisms and their type of interaction?

Match the columns:

Column-$I$	Column-$II$
$(a)$ Camouflage	$(i)$ Dendrobates pumilio
$(b)$ Batesian mimicry	$(ii)$ Horse-shoe bat
$(c)$ Warning mimicry	$(iii)$ Monarch butterfly
$(d)$ Echolocation	$(iv)$ Praying Mantis

Which competition is more intense?

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Both species are harmed	$I$. Predation
$B$. One species is harmed and the other is benefited	$II$. Mutualism
$C$. Both species are benefited	$III$. Competition
$D$. One is benefited while the other has no effect	$IV$. Commensalism

Choose the correct answer from the options given below:

Identify the correct statement/s from the following:
$I$. $Cuscuta$ is a chlorophyllous endoparasite.
$II$. The human liverfluke needs only one host to complete its life cycle.
$III$. The life cycle of endoparasite is more complex due to their extreme specialisation.
$IV$. During the course of evolution the host bird's eggs have evolved to resemble the eggs of the parasitic bird.