The heavily cratered lunar highlands speak to us of an early epoch in the history of the solar system when cratering was much more common than it is today; the present population of interplanetary debris fails by a large factor to account for the abundance of the highland craters. (Carl Sagan, Broca's Brain: Reflections on the Romance of Science)
A) argument; conclusion: The heavily cratered lunar highlands speak to us of an early epoch in the history of the solar system when cratering was much more common than it is today.
B) argument; conclusion: The present population of interplanetary debris fails by a large factor to account for the abundance of the highland craters.
C) nonargument; report
D) nonargument; explanation

Question

Quizplus · Accepted Answer

The first sentence provides an argument, while the second sentence provides a conclusion.

The Heavily Cratered Lunar Highlands Speak to Us of an Early