Concept:An advertising medium that makes only audio impressions communicates entirely through sound, without any visual element.
Explanation:Radio delivers advertisements as spoken words, jingles, or sound effects, so listeners hear the message but do not see it.
Cinema and television combine motion, pictures, and sound, so they create both visual and audio impressions.
Hoardings are large outdoor display boards that rely only on visual messages.
Among the options, radio is the only medium that uses sound alone to reach its audience.
Thus, radio is the correct choice for making only audio impressions.
Answer:B. radio