Synthesize a brief mechanistic explanation for why chylomicrons, once formed in enterocytes, are directed into lacteals instead of directly into blood capillaries.

• A. Chylomicron transport into lacteals is a passive accident of embryologic development with no physiological advantage; mature organisms often reroute chylomicrons directly into portal blood under normal feeding conditions.
• B. Chylomicrons are large, complex lipoprotein particles too large to pass through the small pores of intestinal blood capillaries; lacteals have larger openings and accommodate particle uptake into the lymph, which later drains into the blood, facilitating systemic lipid delivery without immediate hepatic first-pass processing.
• C. Chylomicrons are routed into lacteals because blood capillaries actively hydrolyze chylomicrons on the apical intestinal surface back into monoglycerides and free fatty acids before allowing them entry, thereby preventing intact lipoprotein passage into the circulation.
• D. Enterocytes lack the molecular machinery to secrete chylomicrons toward the interstitium near blood capillaries and therefore default to secreting them into the lymphatic channels which are biochemically specialized to degrade them immediately before systemic release.

Answer: (B)