Beautiful problem.
Problem: The quality of early pieces of blown glass excavated in Italy and Western Europe by far surpass those of pieces from the eastern Mediterranean, when regarded not only in terms of the variety of shapes represented, but also in terms of decorative techniques and functionality.
(A) by far surpass those of pieces from the eastern Mediterranean, when regarded not only in terms of
- Subject-Verb Error: "The quality ... by far
surpass" | Mistake: number mismatch
- Pronoun Error: "The quality" <> "
those" | Mistake: number mismatch
(B) surpasses by far those from the eastern Mediterranean, with regard not only to
- Pronoun Error: "The quality" <> "
those" | Mistake: number mismatch
(C) far surpass that of pieces from the eastern Mediterranean, not only regarding
- Subject-Verb Error: "The quality ... by far
surpass" | Mistake: number mismatch
(D) far surpasses that of the eastern Mediterranean, with regard to not only
- Meaning Error: "that" refers to "the quality"; Thus the meaning of the second part is wrong:
"The quality of the eastern Mediterranean".
(E) far surpasses that of pieces from the eastern Mediterranean, not only with regard to
CORRECT