Harlow Shapley's Original Estimate of the Distance from the Sun

Multiple Choice

Harlow Shapley's original estimate of the distance from the Sun to the galactic center was incorrect because it did not take scattering by interstellar dust into account. Shapley's original estimate was

A) too large because light scattering and absorption by dust made nearer stars look dim-as though they were more distant.
B) too large because scattering by dust made stars look redder-as though they were highly Doppler-shifted and thus more distant.
C) too small because gas and dust tend to reflect light into the path of the beam, thus making stars look brighter and nearer.
D) too large because scattering by dust made stars look redder-as though they were red giants of larger luminosity and thus farther away.