How can the taxonomic category be determined?

Different taxa at the same level are exemplified by:

Read the following statements :
$(i)$ Classification is a single step process.
$(ii)$ Classification involves a hierarchy of steps in which each step represents a rank or category.
$(iii)$ Taxon is a unit of ecological hierarchy.
$(iv)$ Mango does not represent any taxon.
$(v)$ Taxonomic categories are distinct biological entities and not merely morphological aggregates.
How many of the above statements are correct?

The smallest basic unit of classification is ......

$A :$ Biological concept of species is based on reproductive isolation.
$R :$ Most accepted species concept was given by Linnaeus.

Which of the following $statement(s)$ is/are not correct?
$(i)$ Genus comprises a group of related species which has more characters in common in comparison to species of other genera.
$(ii)$ Three different genera such as Solanum,Datura and Petunia are placed in the family Malvaceae.
$(iii)$ In case of plants,classes with a few similar characters are assigned to a higher category called Division.