Answer:
The answer is B. Incorreclty.
Step-by-step explanation:
Unlikely cannot be possible amon the other as it is an adjective, and here we need an adverb, like the rest, so option "d" isn't possible. Ideally means perfectly or according to an ideal so this sounds rather strange according to this context. Succinctly means clearly or briefly and well, we cannot "briefly assume" we either assume or not, as a whole. And finally the divergence or in other words, difference, led the Western Historians to incorrectly assume something from the others.