A 58-year-old patient with chronic low-back pain has lumbar disc-space narrowing and adjacent vertebral endplate sclerosis on CT. Which normal nutrient-delivery pathway to the central nucleus pulposus may be compromised by these changes?

Radial diffusion from vessels at the outer annulus

Load-driven convection across the vertebral endplates

Diffusion from vertebral capillaries across the endplates

Direct perfusion through capillaries within the nucleus

Active transport through the endplate extracellular matrix