Final answer:
A suspension requires a "shake well" label and oral administration is the most appropriate and convenient route for treating systemic infections at home.
Step-by-step explanation:
The dosage form that requires a "shake well" auxiliary label is c) Suspension. Suspensions are liquid preparations that contain solid particles dispersed throughout a liquid phase in which the particles are not fully dissolved. Because the solids can settle at the bottom of the container, it is important to shake the suspension well before use to ensure that the dose taken is homogeneous and delivers the correct amount of medication.
Regarding routes of administration for systemic infections, A. oral administration is often the most appropriate and convenient for home use. Oral medication is easy to self-administer, does not require the assistance of a healthcare professional, and is therefore suitable for use outside of a clinical setting. Intravenous, topical, and other parenteral routes typically require a healthcare professional and are less convenient for home use.