The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
The International code of nomenclature for algae, fungi, and plants (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". It was formerly called the International code of botanical nomenclature (ICBN).
So, the answer is- Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.