Remnants of a meteorite that exploded in Siberian sky and scattered over 400 square km in and around lake baikal
has been dated to be 1.23 Billion years old and thus is evidence of the earliest known Meteor impact on earth.

A. has been dated to be 1.23 Billion years old and thus is
B. has been dated at 1.23 Billion years old and thus
C. have been dated to be 1.23 Billion years old and thus are
D. have been dated as being 1.23 Billion years old and thus
E. have been dated at 1.23 Billion years old and thus are

Practice Test 2. Q.23

Please give me the difference between the usage of the idiom structure.
Is it "dated at" or "dated to be"

Thanks.

Answer E. "Remnants" pairs with "have been" so eliminate A and B. Idiom is "dated at" so eliminate C and D. "Dated to be" is incorrect.

Thanks
But a lot of people say that in the current context "dated to be" is correct, because the process of dating the remnants is done by someone. Like "estimated to be"

Language does change over time. Generally, though, the official test is going to either (1) stick with stuff that isn't in the process of changing or (2) hold to the old, official rules (such as - everyone uses plural pronouns nowadays when using "everyone," "everybody" etc, but the test counts this as wrong. eg "Everybody turn off their phones" is wrong, though we all say things like that every day).