I wanna say it is b secondary growth
Answer:
It is the smallest and basic unit of classification. Taxonomic studies consider a group of individual organisms with fundamental similarities as a species. Thus all the individual members belonging to particular species show all similar characters and can breed among themselves to produce a similar type of organism.
<u><em> Thank You</em></u>
Wow that is a lot of reading. You should be wise and do it yourself. To much sorry .