Which of the following is/are true concerning wound fibroblasts? A. Fibroblasts synthesize and secrete collagen molecules. B. Wound fibroblasts are derived from blood-borne precursor cells. C. Fibroblasts migrate to a wound along fibrin strands, which are used as a scaffold. D. Large amounts of fibrin or blood clot can act as a physical barrier to fibroblast penetration, which delays normal wound healing.