Which group of animals exhibits the highest species richness?

More conservative and scientifically sound estimate made by Robert May places the global species diversity at about

What percentage of the world's total land area does India occupy (in $\%$)?

Animals account for more than $P$ of all species recorded. Even if we combine all plant species (algae,fungi,bryophytes,gymnosperms,and angiosperms),they account for no more than $Q$ of the total percentage.

According to the $IUCN$ Red List $(2004)$, $784$ species have become extinct in the last $500$ years. Match the extinct species given in Column-$I$ with their respective numbers in Column-$II$.

Column-$I$	Column-$II$
$(P)$ Vertebrates	$(I)$ $338$
$(Q)$ Invertebrates	$(II)$ $87$
$(R)$ Plants	$(III)$ $359$

Which one of the following has the highest number of species in nature?