Which can be excluded from a list of evidence that supports the claim that an asteroid colliding with Earth caused a mass extinction?(1 point)

Single-celled and multicellular organisms are found in layers of rocks on Earth.

The Chicxulub Crater was discovered on the Yucatan Peninsula of Mexico in 1978.

The rare metal iridium was found in rocks above and below the line where dinosaur fossils disappeared.

Dinosaur fossils are plentiful in one layer of rock and absent in the layer above.
(Is it b?)