How does the use of alliteration in these lines influence the reader's emotions?

and maggie discovered a shell that sang

so sweetly she couldn't remember her troubles, and

(from \"Maggie and Milly and Molly and May\" by E. E. Cummings)

AIt creates a mental image of the seashore.

BIt gives a musical effect to the singing shell.

CIt emphasizes the sweetness of the song.

DIt describes how Maggie forgot her troubles.