问一道SC!!!纠结!请大牛现身!关于同位语和独立主格

At the turn of the twentieth century, forest covering as much as 90 percent of Thailand and accommodating as many as 300,000 elephants, a third of them domesticated and performing various essential tasks.

A.covering as much as 90 percent of Thailand
and accommodating as many as 300,000 elephants, a third of them
B.covering as much as 90 percent of Thailand
accommodated as much as 300,000 elephants, and a third of them were
C.covered as much as 90 percent of Thailand
and accommodated as much as 300,000 elephants, with a third
D.covered as much as 90 percent of Thailand
and accommodated as many as 300,000 elephants, a third of them
E.covered as much as 90 percent of Thailand
and accommodating as many as 300,000 elephants, with a third of them
答案D 我想问ELEPHANTS后面的结构到底是同位语还是独立主格 我觉得是后者呢,可搜以前的帖子说是同位语 不解*-*
请教如何区分!!!