I dont understand

Read the excerpt from Heart of a Samurai.

"Kuroshio," Denzo said. "The Black Current." His voice was as dark as the water that surrounded them. Everyone stared at the wide stripe of indigo water which usually flowed north, toward home. This year, for reasons they did not understand, the current flowed southeast.

Which best states how the excerpt keeps readers interested in the story?

It creates suspense.
It explains a past event.
It describes a conflict.
It quickens the story’s pace.