Nice explanations folks, updated the post with OA and OE.
Unlike Acanthus, whose wedding was sparsely attended being married in a low profile community church, Tom’s was attended by more than seven-hundred guests and his marriage’s location lies in a famous 15th-century Odescalchi Castle in Bracciano, Italy.
(A) being married in a low profile community church, Tom’s was attended by more than seven hundred guests and held in a 15th century Odescalchi Castle which is famous and in Bracciano, Italy.
The subordinate clause “whose funeral was sparsely attended being married in a low profile community church” is grammatically awkward and ambiguous in meaning. Moreover, the sentence makes an illogical comparison between Acanthus and Tom’s wedding. Finally, the phrase “which is famous” is unnecessarily wordy and the construction “famous 15th century Odescalchi Castle “would be more appropriate.
(B) being married in a low profile community church, Tom’s wedding was attended by more than seven hundred guests and his marriage’s location lies in a famous 15th-century Odescalchi Castle in Bracciano, Italy.
Like (A), (B) also contains a grammatically awkward subordinate clause. Second, while the introduction of “wedding” makes the possessive “Tom’s” unambiguous, the sentence still illogically compares “Acanthus” to “Tom’s wedding.” Finally, this choice creates an awkward construction “and his marriage’s location lies…”; this can be clearly stated by “and held in…”
(C) and he was married in a low profile community church, Tom had a wedding attended by more than seven hundred guests and held in a famous 15th century Odescalchi Castle in Bracciano, Italy.
“Acanthus” is followed by two clauses, “whose wedding was sparsely attended” and “he was married in a low profile community church.” The second of these clauses is incorrect because it should be a subordinate clause modifying Acanthus, and should therefore start with "who was buried"; second, it should be parallel to the first clause, and should therefore start with "who was buried". Finally, it makes an illogical assertion - “Unlike Acanthus, he “Acanthus” was married….”.
(D) and who was married in a low profile community church, Tom’s wedding was attended by more than seven hundred guests and held in a famous 15th century Odescalchi Castle in Bracciano, Italy.
This choice makes an illogical comparison between "Acanthus" and “Tom’s wedding.". This choice corrects the first subordinate clause error by introducing the clause as “who was married…”
(E) and who was married in a low profile community church, Tom had a wedding attended by more than seven hundred guests and held in a famous 15th century Odescalchi Castle in Bracciano, Italy.
CORRECT. “Acanthus” is modified by two subordinate clauses, “whose wedding was attended….” and “who was married ….,” each properly introduced by the relative pronouns “whose” and “who” respectively. In addition, “Acanthus” is now logically compared to “Tom.” Moreover, the later part of the underlined portion does not contain any wordiness or ambiguity.