What Is Still Lacking in the Hypothesis of an Asteroid

Multiple Choice

What is still lacking in the hypothesis of an asteroid impact as the cause of the end-Cretaceous mass extinction?

A) evidence that an asteroid hit Earth at the time of the extinctions 65 million years ago)
B) a convincing explanation of why mammals radiated after the event
C) evidence of the location where an asteroid hit Earth
D) a convincing explanation of why some lineages survived while others vanished