代脉的脉象特点是（）。

A.缓而时止，止无定数

B.数而时止，止无定数

C.数而时止，止有定数

D.脉来迟缓，良久一至

E.脉迟时止，止有定数

Marko Tskitishvili, an economist, has been studying the drop in the price of the average household computer in the U.S. and wonders if computers should still be considered a luxury good or if it has now become a normal good. He conducts a survey of 500 people and finds the following:

Assume that 1998 is the base date. Based on the above data, Tskitishvili would conclude that a computer is a:（）

A. luxury good with income elasticity of 1.01.

B. normal good with income elasticity of 0.84.

C. luxury good with income elasticity of 1.18.