"But the bird was almost out of sight now and nothing showed on the surface of the water but some patches of yellow, sun-bleached Sargasso weed and the purple, formalized, iridescent, gelatinous bladder of a Portuguese man-of-war floating close beside the boat."

This passage is an example of
A. a flashback.
B. characterization.
C. descriptive language.
D. a simile.