Final answer:
Phenolics are the disinfectants that do not act by disrupting the plasma membrane. They denature proteins and disrupt membranes instead. Quaternary ammonium compounds, on the other hand, do disrupt membranes.
Step-by-step explanation:
Among these disinfectants, the one that does not act by disrupting the plasma membrane is Phenolics. Phenolics are stable, long-acting disinfectants that denature proteins and disrupt membranes. They are commonly found in household cleaners, mouthwashes, and hospital disinfectants.
On the other hand, Quaternary ammonium compounds (quats) do disrupt membranes and are used in household cleaners, skin disinfectants, oral rinses, and mouthwashes.