1. Morphospecies are groups of individuals that are morphologically similar and clearly distinguishable from individuals of other groups.
2. A group of interbreeding individuals that are isolated reproductively from all other groups is called Biospecies.
3. Linneon are the taxonomic species distinguished on the basis of morphological characters.
4. Those species which are present in the living world are known as neontological species.
So, the correct option is 'Linneon'.