An analyst gathered the following data about three stocks

If the risk-free rate is 8% and the risk-premium on the market is 7%, is each stock undervalued, properly valued, or overvalued Stock A Stock B Stock C（）

A. Undervalued Properly valued Overvalued

B. Overvalued Overvalued Properly valued

C. Overvalued Properly valued Undervalued

男性，25岁，上腹疼痛5年余，呈间歇发作，空腹痛为主，伴反酸、嗳气，近日出现黑便，呈柏油色，上腹疼痛减轻，心悸、出冷汗，查体：血压100／70mmHg，上腹部轻压痛，肝、脾未触及，化验：血红蛋白90g／L，大便隐血阳性。

最有意义的确诊手段是（）。

A.开腹探察

B.纤维胃镜

C.B型超声

D.上消化道造影

E.胃液分析