During an experiment, readings for blood presure in a persons body were found to be constant. however when measured by a different blood pressure cuff, the readings different by 15 points for each reading. this difference indicated that the results but

The difference in the given case indicates that the results are reliable but not accurate. Precision is the tendency of an apparatus to provide repeatable quantities, that is, inaccuracies are minor. The application of standard deviation is generally used as a precision error.  

Accuracy refers to the part of an apparatus that provides measures whose average is nearer to the accurate value. It is the reproducibility of an apparatus.  

the statement is true

the real answer is b. scintillation counter