One cue in some choices here is the use of the connector ‘that” proper comparison; ‘Historians maintain that today's royalty’ is vastly different from historians maintain today's royalty’. Now case by case
A. Much like the nobility of old, historians maintain that today's royalty ----
- faulty comparison, nobility compared with historians B. Today's royalty, much like the nobility of old, it is maintained by historians, ----
the pronoun it is grammatically redundant; also distorted meaning the royalty is maintained by the historians C. Much like the nobility of old, historians maintain today's royalty:
the absence of connector implies that the historians maintain the royalty: Comparison too is faulty with nobility compared with historians
D.Historians maintain that today's royalty, much like the nobility of old, ---
The best choice. E. Historians maintain, today's royalty, much like the nobility of old, ---
The phrase today’s royalty offset within commas renders it inessential; At best, the comma after maintain should have been dropped.
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