• Programmed Cell Death: Apoptosis is an active, gene-regulated, energy (ATP)-dependent mechanism of programmed cell death wherein individual cells activate intrinsic biochemical suicide pathways.
• Morphological Hallmarks: Characterized by cell shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), and blebbing of the plasma membrane into intact apoptotic bodies that are rapidly phagocytosed without eliciting inflammatory responses.
• Contrasting Processes:
• Oncosis: Accidental, non-programmed cell death caused by energy depletion and membrane failure leading to cellular swelling, blebbing, rupture, and acute inflammation.
• Autolysis: Post-mortem enzymatic self-digestion of cells by their own lysosomal enzymes.
• Putrefaction: Post-mortem decomposition of tissues by saprophytic bacteria accompanied by gas and foul-smelling catabolites.

Correct option: (3) Apoptosis

Evaluating the Assertion and Reason concerning Inflammation – definitions associated with inflammatory phenomenon:

The correct answer is Option 1: Both (A) and (R) are true and (R) is the correct explanation of (A).

• Matching Vascular and Cellular Terminology in Inflammation:
• Margination $\longrightarrow$ (III) Alignment of leukocytes along vascular endothelial surfaces: During acute inflammation, slowing of blood flow (stasis) allows white blood cells to move from the central axial stream toward the periphery of the vessel lumen.
• Diapedesis (Transmigration) $\longrightarrow$ (I) Emigration of leukocytes across the capillary basement membrane: Active squeezing of leukocytes through endothelial intercellular junctions into perivascular tissues.
• Chemotaxis $\longrightarrow$ (IV) Directional migration along a chemical concentration gradient: Leukocyte locomotion guided by chemoattractants (C5a, leukotriene $B_4$, bacterial formyl peptides).
• Opsonization $\longrightarrow$ (II) Coating of microbes to facilitate phagocytic recognition: Coating antigens with antibodies (IgG) or complement fragments (C3b, iC3b) recognized by phagocyte Fc and CR1 receptors.
• Conclusion: (A) - (III), (B) - (I), (C) - (IV), (D) - (II) (Option 3).

Correct option: (3) (A) - (III), (B) - (), (C) - (IV), (B) - (I)