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Order of draw prevents additive carryover that can alter test results. Whether using an evacuated system or transferring from a syringe via a safety device, the sequence remains the same: blood cultures first (to minimize contamination), then sodium citrate (light blue) for coagulation (preserving the 9:1 ratio), followed by serum tubes, heparin (green), EDTA (lavender/pink), and glycolytic inhibitor (gray). Option C reflects this standard. Reversing the order risks EDTA carryover (falsely low calcium, falsely high potassium) or clot activator contamination affecting coagulation tests. Option D is incorrect—device choice does not change biochemical interactions between additives. During transfer, allow the tube’s vacuum to draw blood (do not force with the syringe plunger) and gently invert each tube as labeled. This maintains specimen integrity, ensures valid results, and aligns with widely taught preanalytical guidelines.