Like Edvard Grieg, whom the Scandinavians long refused to recognize, the Italians’ disregard for Verdi persisted for a decade after his critical acclaim in France and Austria.
(A) Like Edvard Grieg, whom the Scandinavians long refused to recognize, (incorrect: comparison error)
Like x, y: like E. G., disregard is incorrect
(B) Like Edvard Grieg, who the Scandinavians long refused to recognize, (incorrect: comparison error)
The same as option A has
(C) Just as Edvard Grieg was long refused recognition by the Scandinavians, (incorrect: pronoun error)
Just as x, y: as shows the similarity of two actions or clauses while like shows the similarity between two nouns
(D) Just as the Scandinavians long refused to recognize Edvard Grieg, so (incorrect: idiomatic error)
Just as x, so y is incorrect: correct idiom is just as x, y
(E) Like the Scandinavians’ long refusal to recognize Edvard Grieg, (the best option)
Correct comparison: like refusal, disregard