请问在这题里grow to be与grow as …… as的区别

The 32 species that make up the dolphin family are closely related to whales and in fact include the animal known as the killer whale, which can grow to be 30 feet long and is famous for its aggressive hunting pods.

我不是牛牛，只是说说个人想法：

1、B中的growing as big as 30 feet long 不妥，big 与long不是同等的形容，要说应该是as long as 30 feet，

2、而且一般而言grow 不接as, 类似的还有believe to be, estimate to be

3、growing表示一个正在进行的动作，而句意应该是表示“可能会长到...”

谢谢，明白很多了。