In 1959, the film industry debuted Smell-O-Vision, a technology in which theaters were fitted with specialized vents that emitted odors at specific points in a ________ as the scent of roses when roses appeared in a scene. Smell-O-Vision failed to impress, however, with one reviewer declaring it "briefly weird and not very interesting."

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