The correct answer is C: To maximize efficiency. Antenna loading coils should have a high ratio of reactance to resistance (high Q) to maximize efficiency. High Q means low losses - most of the energy is stored in the magnetic field (reactance) rather than lost as heat (resistance). Loading coils have both inductive reactance (XL) and resistance (R). The Q (quality factor) is XL/R. High Q means the reactance is much larger than the resistance, so losses are low. A high-Q coil stores energy efficiently with minimal loss. Low-Q coils (high resistance relative to reactance) waste power as heat, reducing antenna efficiency. This is why loading coils are made with low-resistance wire and sometimes use ferrite cores to increase inductance (reactance) without adding much resistance.