GMAT Sentence Correction (SC) | A group of paleontologists recently announced that a site in

Hi sayan

I have a question doubt in the below question. Could you please help me clarifying it.

A group of paleontologists recently announced that a site in Utah has yielded fossils of some of the biggest armored dinosaurs ever found,and that they were at least 25 million years older than any similar dinosaur type previously found in North America.
A. and that they were at least 25 million years older than any similar dinosaur type previously
B. and they are at least 25 million years older