Final answer:
Reticular fibers are found in the matrix of reticular connective tissue.
Step-by-step explanation:
The organic portion of reticular connective tissue is made up of reticular fibers. Reticular fibers are thin strands of collagen that form a network of fibers to support the tissue and other organs to which it is connected. Reticular connective tissue is distinguished by the prevalence of reticular fibers within its matrix (Option C). These fibers are composed of thin collagen strands arranged in a branching network, forming a supportive framework for various organs. Collagen fibers (Option A) are indeed present in connective tissues, including reticular tissue, but reticular fibers specifically contribute to the unique structure of reticular connective tissue. Elastic fibers (Option B) provide elasticity to tissues and are not the primary component of reticular tissue. Fibroblasts (Option D) are cells involved in the synthesis of extracellular matrix components, including fibers, but they are not the fibers themselves.