A. Exterior noise
C. Interior noise
I have been asked this question in a national level competition.
This key question is from Acoustics topic in section Acoustics and Ventilation of Construction & Building Materials
To explain I would say: The remedies to correct loudness defect consist in arranging hard reflecting surfaces near the source of sound and in adjusting the absorption of the hall so as to give an optimum time of reverberation. Also, the location of loudspeakers should be carefully adjusted.