E4C11 - Amateur Extra Class

E4C11 : Why does input attenuation reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?
A The attenuator has a low-pass filter to increase the strength of lower frequency signals
B The attenuator has a noise filter to suppress interference
C Signals are attenuated separately from the noise
D Atmospheric noise is generally greater than internally generated noise even after attenuation
Correct Answer: Atmospheric noise is generally greater than internally generated noise even after attenuation