Solution

The small projections present on the surface of pineapple fruit represent persistent bracts. Pineapple is a sorosis fruit that develops from spike or spadix or catkin where the juicy and fleshy part is formed from the axis, the bract and the perianth. Bracts (hypsophylls) are special leaves at whose axils the flowers are borne. They are not always present, and if present, the flower is called bracteate. Bracts may drop off early (deciduous) or they may be persistent. When bracts are present, they serve for the protection of flower buds in the young stage.Morphologically it can be said that a bract may be formed by the entire phyllopodium or a part of it.
So, the correct answer is 'Persistent bracts'