A、Declining home production. B、The prolonged tax policy. C、The decreasing GDP in the US. D、The economic downturn of the country.

The Commerce Department said sales fell by 11.3% to a seasonally-adjusted annual rate of 355,000 homes, down from a revised 400,000 in October. [3]The fall reflects the extension of first-time buyer tax credits, which had become due in November. The total was far lower than analysts had expected, and the data wiped out early gains in shares on Wall Street. Home sales had been boosted by buyers looking to take advantage of the tax credit, but now that they have been extended to April, the incentive to buy has disappeared, analysts say. [4]As a result, "buyer traffic is likely to be flat until spring," predicted Mark Vitner at Wells Fargo Securities. The median sales price for November was $217,000.
3. What’s the main reason for the dropping in new home sales?
4. What do we learn from Mark Vitner’s remark?