OG 12 SC-140题 到底选哪个好？ “dated at vs dated to be”

gys

原题如下：
140. Rock samples taken from the remains of an asteroid
about twice the size of the 6-mile-wide asteroid that
eradicated the dinosaurs has been dated to be 3.47
billion years old and thus is evidence of the earliest
known asteroid impact on Earth.
(A) has been dated to be 3.47 billion years old and
thus is
(B) has been dated at 3.47 billion years old and thus
(C) have been dated to be 3.47 billion years old and
thus are
(D) have been dated as being 3.47 billion years old
and thus
(E) have been dated at 3.47 billion years old and
thus are


看到一位高人的解释：
Rock samples have been dated to be 10,000 years ago.
-- Rock samples have analyzed by sceientist to be at least 10,000 old.

Rock samples have been dated at 10,000 years ago
-- This is not possible. First, science was not that fancy 10,000 years ago to be able to know the age of rock sample. Second, even it is the case, you cannot use past participle and you have to change to past tense.

觉得挺有道理， 但OG解释说 C Dated to be is not idiomatic.  这个dated 到底怎么用呢？

wjd0315

同问。。。有没有NN可以把date的用法总结一下？date好像也可以加+to的我印象中~~~

pirate舟

date at ... old
date to ... ago