问：英语词汇单选题Having been told by the doctor that the result of t

问：英语词汇单选题
Having been told by the doctor that the result of the medical examination was______,I______ a sigh of release.
A.positive;gave out
B.negative;let out
C.sensitive;let out
D.positive;gave off
E.constructive;let off
只有一个答案是最合适的
选对且给出最合理解释的采为答案