Task: Question Answering
Input (English): A geologist found several types of seashell fossils in a rock layer. Which is the best conclusion about the rock layer?  
 (A) The rock was once buried under a swamp. (B) Water from a river washed across the rock. (C) The rock was once sediment at the bottom of an ocean. (D) Migrating animals dropped the seashell into the rock.
Output (English): C