Here's the version created via the use of (B).
(B) In her book illustrations, carefully coordinating them with her narratives, Beatrix Potter capitalized on her keen observation and love of the natural world.
The modifier "carefully coordinating them with her narratives" is problematic in two ways.
One issue is that the participial phrase "carefully coordinating them with her narratives" has to modify the clause "Beatrix Potter capitalized ...." This modification is illogical, because it is not logical that Beatrix Potter would have capitalized on her keen observation and love of the natural world by or in the process of carefully coordinating her illustrations with her narratives. The two actions have little to do with each other. So, modifying the clause with the participial phrase results in the sentence's conveying a nonsensical meaning.
Secondly, "In her book illustrations, carefully coordinating them" is not logical. It modifies what Beatrix Potter did "in her book illustrations" by saying what she did
to her book illustrations, "coordinating them." It does not make sense to mix discussion what she did in and to her illustrations in this manner.