听力原文： Nokia warned that the U. S. slowdown is now extending to other economies, and said that is cutting into demand for Nokia s handsets, and for its growing mobile infrastructure business.
In April, a more optimistic Nokia said it was on course for a 20 percent sales growth this quarter. That forecast has been cut in half. Tuesday s warning knocked a whopping $31 billion off Nokia s market capitlization. Nokia joins rivals Motorola and Ericsson in warning about sales. The rate of new phone purchases has slowed dramatically in Europe, with customers reluctant to trade up to new handsets.
Why has the rate of new phone purchases slowed in Europe？

A. Because of the warning about sales.
Because the customers are reluctant to trade up to new handsets.
C. Because of cutting into demand for handsets.
D. Because of the US slowdown.