B is the correct answer. Hope that helped. If you don't understand why PM me and i can explain :)
Answer:
C.how to tell whether the test was accurate
Explanation:
This is because, after the test, Safiya's brother should be able to check if the test carried out was accurate and not wrong as directed.
This could be done through series of validation technique rather than assuming that the test carried out was correct.
Wait....Exactly what are you confused about?
The answer is than yours.