Final answer:
MAdCAM-1 is the vascular addressin on intestinal mucosal endothelial cells that binds integrins on gut-homing effector lymphocytes, helping with immune surveillance in the gut. The correct option is d.
Step-by-step explanation:
The vascular addressin found on endothelial cells of intestinal mucosa that binds to integrins of gut-homing effector lymphocytes is MAdCAM-1. This molecule is essential for the adhesion of lymphocytes to the endothelium and for their subsequent trafficking to the intestinal mucosa, a process critical for proper immune surveillance and response in the gut.
MAdCAM-1 is particularly important in the context of Mucosa-Associated Lymphoid Tissue (MALT), where it facilitates the immune system's interaction with antigens presented in the gut.
Hence, Option d is correct.