Having returned from the ocean to the stream where it was born, an adult salmon’s life cycle ends when it spawns and dies, after which its offspring start the cycle anew.

Which choice completes the text so that it conforms to the conventions of Standard English?

A. an adult salmon’s life cycle ends when it spawns and dies,

B. an adult salmon spawns and dies, completing its life cycle,

C. the spawning and death of an adult salmon complete its life cycle,

D. the life cycle of an adult salmon is complete when it spawns and die,