Old Navy Lace Bralette with Front closure fits like Large 40/B

Old Navy Lace Bralette with Front closure fits like a Large, though tag is XL. I measured the band and it stretches to 20", making it a 40" band. I am a C/D cup and think this would best fit a B cup. Color is best represented in the 2nd and 3rd photo, it's a vibrant lilac/fuschia color, pink leaning. Bra is new.