大全632，老帖就2个，再讨论一次吧

Selling several hundred thousand copies in six months, the publication of “Maple Leaf Rag” in 1899 was an instant hit, helping to establish Scott Joplin as the preeminent ragtime composer.

A)    Selling several hundred thousand copies in six months, the publication of “Maple Leaf Rag” in 1899 was an instant hit, helping to establish Scott Joplin as the preeminent ragtime composer.

B)      The publication in 1899 of “Maple Leaf Rag” was an instant hit: in six months they sold several hundred thousand copies and it helped establish Scott Joplin as the preeminent ragtime composer.

C)     Helping to establish Scott Joplin as the preeminent ragtime composer was the publication of “Maple Leaf Rag” in 1899, which was an instant hit: it sold several hundred thousand copies in six months.

D)     “Maple Leaf Rag” was an instant hit: it helped establish Scott Joplin as the preeminent ragtime composer, published in 1899 and selling several hundred thousand copies in six months.

E)      Published in 1899, “Maple Leaf Rag” was an instant hit, selling several hundred thousand copies in six months: it helped establish Scott Joplin as the preeminent ragtime composer.

我选了A，答案是E，看了才想起来SELL这词用起来有点特殊，但没总结过，哪位高手有这心得，另外，E有一个冒号，冒号后的it指代什么呢？it肯定不能指代一句句子啊（除了形式主语等特殊情况下），请教了