During a histology practical, a medical student observes two tissue samples under the microscope. Sample A shows cells with condensed chromatin arranged at the nuclear periphery, intact cell membranes with membrane blebbing, and no inflammatory cells. Sample B shows cells with swollen nuclei, dispersed chromatin, ruptured membranes, and surrounding acute inflammatory infiltrate. Which single feature most reliably distinguishes Sample A (apoptosis) from Sample B (necrosis)?