Answer:
The correct answer is - Chondroblasts; Fibroblasts
Explanation:
Mesenchymal progenitor cells will form chondrocytes combinedly called Chondroblasts that is responsible for the secretion of the rubbery matrix of cartilage.
Fibroblast on other hand produces fibers and ground substance. These ground substances and fibers make the matrix of the fibrous connective tissue.