Sentence correction veritas q

Dear meeks,
I see you have already gotten a few responses, but I am happy to respond. For future reference, when you post a question, please cite the source. This is a Veritas question. Their questions are usually good, although I do not have a high opinion of this question.

Choices (D) & (E) are clearly wrong, so we'll ignore them.

The split between (B) & (C) is dubious. It comes down to: who or what should be the subject of "embellished"? Certainly it is correct to say that the monks embellished the calligraphy, but it also falls within acceptable usage to say that the illuminations, the pictures, embellished the calligraphy. There is absolutely nothing wrong with that, and so there is absolutely nothing wrong with the construction in (B), where the action of "embellishing" would refer to the "manuscript illuminations." Both (B) & (C) are perfectly correct.
For that matter, (A) is also an acceptable answer: it's not ideal to separate the subject that much from the verb, but it's not "wrong." Choice (A) is well within the bounds of what would be an acceptable answer on the GMAT.

Overall, this is a question with as many as three candidates for the "best answer." Good SC have one clear right answer, and four choices about which something is unambiguously, non-negotiably wrong. This question does not adhere to that standard, so it is a very poor question. This is unusual, because I have said, most Veritas questions I have seen tend to be high quality.

Let me know if you have any further questions.
Mike