To solve the problem, we need to identify the connective tissue types where the cells secrete fibers of collagen or elastin. Let's analyze each option:
Cartilage is a connective tissue in which chondrocytes (cartilage cells) secrete collagen fibers. Cartilage provides support, flexibility, and strength to structures. Hence, cartilage secretes collagen and sometimes elastin fibers.
This tissue stores fat but does not actively secrete collagen or elastin fibers as its primary function. The main function of adipose tissue is to store energy in the form of fat and insulation. Thus, adipose cells do not typically secrete these fibers.
This connective tissue is primarily involved in transport and does not have fibers like collagen or elastin. Blood does not secrete these types of fibers because its matrix is a liquid plasma, which is crucial for nutrient and gas transport.
Areolar tissue is a loose connective tissue where fibroblasts secrete both collagen and elastin fibers. These fibers contribute to the tissue's flexibility and strength.
Therefore, the correct answer is: A, D, C, and E only, from the options provided, the most appropriate connective tissues that commonly secrete fibers of collagen or elastin are Cartilage and Areolar tissue.