The correct option is D persistent bracts
Pineapple is a sorosis fruit. It develops from spike or spadix or catkin where the juicy and fleshy part is formed from the axis, the bract and the perianth. Bracts are specialized plant structures that serve varied functions such as attracting pollinators and protecting inflorescences (flower structures).
The small projections present on the surface of pineapple fruit represent persistent bracts.