(d) A music streaming platform that suggests songs and playlists based on user listening history.
A recommendation system suggests items to users based on their past behaviour or preferences. Option (d) directly matches this — the platform analyses listening history to suggest relevant songs. Options (a), (b), and (c) describe a product catalogue, a search engine, and a review display system respectively, none of which involve personalised recommendations. The textbook also cites Spotify/Netflix-style platforms as classic examples of recommendation systems using clustering/unsupervised learning.