Large deposits of the rare mineral nahcolite formed in salty lakes 50 million to 52 million years ago during the Eocene epoch.
Your task
Break the argument into its conclusion and evidence, then do exactly what the question stem asks with that structure.
Common trap
Answers that sound relevant to the topic but don't connect to the argument's actual reasoning.
Winning move
Predict what a right answer must do, then test each choice against the conclusion-evidence gap.