. Collagen fibers are secreted by
A: Mast cells
The main structural protein of varied connective tissues in animals is Collagen.
Fibroblast cells secrete it.
It is found in fibrous tissues, such as ligaments, tendons, and skin.
Its appearance is elongated fibrils type.
Final Answer :
Hence, the correct option is D, i.e. Fibroblasts.