请教一道PP阅读

大家好,此题答案是D,可我觉得C也对吧?请牛牛帮忙看看,谢谢.

During the late nineteenth century, many

architects in the United States considered wood,

an abundant North American building product, to

be nature's true material, and they anticipated that

a native style of architecture would emerge from its

proper use.  Other architects, however, thought that

wood had serious liabilities and were thus attracted

to solid construction of stone, brick, or concrete.  Their

choice was based on economic reasons---

when the price of wood soared, as it occasionally

did, they questioned the financial advantages of

timber and predicted that it would be even more

expensive as American forests became depleted.  

They also argued that even though the initial cost of

a timber house was less than that of one in brick,

stone, or concrete (and they often disputed this

point), the long-term expense was greater.  They

pointed out that unlike the materials used in solid

construction, timber deteriorated quickly, needed

constant upkeep, and attracted harmful insects and

rodents.  More important, timber was combustible.  

At a time when major areas of American cities were

frequently destroyed by fires and when new suburbs

did not have efficient fire-fighting systems, the fact

that masonry was fireproof was a compelling argument

in favor of solid construction.

181. The word it in the passage refers to

    solid construction  

    choice  

    price  

    timber  

谢谢所有楼上的