When it comes to modifier questions - or really any SC question - it helps to start by identifying the core of your sentence: what are the subject(s) and verb(s), and how do the other sentence elements relate to them?

Medieval monks, through their manuscript illuminations, meticulously embellishing the elaborate calligraphy, communicated their interpretive understanding of the texts they illustrated.

The core of the sentence here is "monks communicated." The other pieces are modifying: "through their manuscript illuminations" tells us how they communicated, as does "meticulously embellishing." Because they're telling us how, these are both adverbial modifiers.

The problem, though, is that we can't stack two modifiers in a row if they're modifying the same thing. Effectively, what we have is:
Subject, adverbial modifier, adverbial modifier, verb...
We need to conjoin these modifiers (if they're modifying the same thing), or change one of them to modify something else.


A) Medieval monks, through their manuscript illuminations, meticulously embellishing the elaborate calligraphy, communicated
Two adverbial modifiers modifying the same thing.

B) Through their manuscript illuminations, meticulously embellishing the elaborate calligraphy, medieval monks communicated
Same issue here - the modifiers were simply moved to the beginning of the sentence, but it's still two adverbial modifiers modifying the same thing.

C) Through their manuscript illuminations, with which they meticulously embellished elaborate calligraphy, medieval monks communicated
Here, the idea of "embellishing" has been changed. The "with which" tells us that this is now modifying the word that came before it: "illuminations." It's a modifier nested within another modifier - in other words, they're modifying two different things. CORRECT

D) Meticulously embellishing the elaborate calligraphy, medieval monks, through their manuscript illuminations communicated
Here, the modifiers aren't directly in a row, but they're still both adverbial modifiers trying to modify the same thing.

E) Medieval monks, through their manuscript illuminations, meticulously embellished them and communicated
This sentence now makes "embellished" a verb rather than a modifier. This fixes the modifier issue, but it changes the meaning. "Embellished" and "communicated" are not parallel ideas.
Furthermore, the use of "them" is incorrect. We can't use "their" to refer to monks and "them" to refer to the manuscripts in the same sentence.

Here's another example of the two-modifiers-in-a-row rule: https://www.beatthegmat.com/tricky-modif ... tml#637463

Great question! When it comes to modifiers, we want to think about 2 things - meaning and structure. From a meaning perspective, you're sort of right the illuminations are being modified (as we see in C). But if "embellishing" were modifying "illuminations," that would imply that the illuminations were doing the embellishing, which doesn't make sense.

From a structural perspective as well, we know that "embellishing" can't be a noun modifier. When a present participle comes after a comma, it modifies the entire clause before the comma:
I told a story, embellishing it with details that weren't quite true.
Here, the participle is describing how I told the story.

If a present participle is used without a comma, though, then it's a noun modifier:
The girl embellishing the truth is nothing more than a liar.
Here, "embellishing" is simply describing the girl.

Does this clarify?