Read the given paragraph and answer the given question :

Parasitism has evolved in many taxonomic groups from plants to higher vertebrates. Many parasites have evolved to be host specific in such a way that both host and the parasite tend to co-evolve. In accordance with their life styles, parasite evolve special adaptations and complex life cycle.

Parasites harm the host by :

Reducing its survival, growth, reproduction and population density

The correct answer is Option (3) – Reducing its survival, growth, reproduction and population density

Many parasites have evolved to be host-specific (they can parasitise only a single species of host) in such a way that both host and the parasite tend to co-evolve; that is, if the host evolves special mechanisms for rejecting or resisting the parasite,the parasite has to evolve mechanisms to counteract and neutralise them, in order to be successful with the same host species.

In accordance with their life styles, parasites evolved special adaptations such as the loss of unnecessary sense organs, presence of adhesive organs or suckers to cling on to the host, loss of
digestive system and high reproductive capacity.

Majority of the parasites harm the host; they may reduce the survival, growth and reproduction of the host and reduce its population density. They might render the host more vulnerable to predation by making it physically weak.