一老年男性患者，70岁，有高血压病史8年，半年前曾患脑卒中，近三个月来记忆力明显减退，经常记不起刚刚发生的事情，临床最可能的诊断为（）

A.阿尔茨海默病

B.脑血管性痴呆

C.Pick病

D.Lewy体痴呆

E.老年良性健忘症

An investor gathered the following information about two 7 percent annual-pay, option-free bonds: Bond R has 4 years to maturity and is priced to yield 6 percent Bond S has 7 years to maturity and is priced to yield 6 percent Both bonds have a par value of $1000. Given a 50 basis point parallel upward shift in interest rates, what is the value of the two-bond portfolio（）

A. $2044.

B. $2030.

C. $2086.