Beatrix Potter, in her book illustrations, carefully coordinating them

Hi badplanner,

Beatrix Potter, in her book illustrations, carefully coordinating them with her narratives, capitalized on her keen observation and love of the natural world.

Choice B: In her book illustrations, carefully coordinating them with her narratives, Beatrix Potter
In this choice, we have verb-ing modifier “coordinating” after comma. The rule is if the verb-ing modifier is placed after comma, then it modifies the entire preceding clause. However, in this choice, there is not clause before the comma.

You are correct in saying that Beatrix Potter did the action of “coordinating” and logically it should refer to Potter. However, the placement of this modifier is such that it fails to do what it should do. Hence, logically “coordinating” is modifying Potter but grammatically it is not because of it placement after comma.

Let’s compare this choice with the example you have presented:

Walking along the road, Beatrix Potter saw several types of flowers.

There is no modifier error in this sentence. The sentence begins with the verb-ing modifier “walking”, and correctly modifies the subject of the main clause “Beatrix Potter” because she did the action of walking. Notice here that there is no comma before the verb-ing modifier.
In choice B of this OG question, we do have a comma before the verb-ing modifier. Thus it should modify the preceding clause. But there is no clause there. I also quite don’t agree to all the explanations of OG. They have terrific questions but not all the explanations are that good.

The usage of Verb-ing Modifiers has been covered in excruciating details in the "Modifiers - Verb-ing" Concept in the Level 1 Preview Concepts. This section is available for free. Just login to e-gmat.com, register for free and learn the concept.

Hope this helps.
Thanks.
Shraddha