PREP的一道题，请教一下NN

Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive.  Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600.  However, since the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994, the number of Verdlanders receiving the special program information probably did not increase significantly.

Which of the following is an assumption on which the argument depends?

(A) Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.

(B) In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.

(C) Equipping a radio station with RDS technology does not decrease the station's listening area.

(D) In 1996 Verdlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.

(E) The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.

radio station多了，但是radio没多；推出接收这种信号的人没多。

A没大看懂，所以选了D。

NN可以解释下A的意思，以及D为啥不对么？

该论点成立的假设是：1994年有RDS Radio的人几乎都receive the special program，所以到了1996年receive the special program的人数才没有显著增加（因为RDS Radio的数量没有显著增加）。

这是不是是A所说的意思？

哦，将A取非的意思就是说94年以前已经有人住在RDS-equipped的地区了，对吗？这样倒是说得通了。

而D确是反对了前提。

我理解的对么？

D我以为可以看成must be true，而非assumption.

A的意思我看了很久也不是很明白，姑且理解为:1994年后新增电台所增加覆盖的区域（with RDS-equipped radio）比起1994年以前，即使有，也是很少的。A和C相比，多了with RDS-equipped radio.这个是很重要的