Respuesta :
The question is asking you which phrase best explains that the building is old. Your answer should be "Discoloration of ages," which implies that the building has been discolored due to the ages of time that have passed.
Answer: a. discoloration of ages.
The text states that the principal characteristic of the building was "that of an excessive antiquity." It also tells the reader that "the discoloration of ages had been great." Afterwards, the text tells us that besides this, there was little dilapidation and that the structure itself was still standing. Therefore, the best way to exemplify the antiquity was the discoloration of the building.