Troposphere is what I think it is.
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.
Well, Euglena is in phylum Euglenophyta, and Paramecium is in phylum Ciliophora. You can verify that with a quick Google search.
<span>Does that sort of narrow it down? :)</span>