When Testing for Medical Conditions,when Is a High Efficiency Most

When testing for medical conditions,when is a high efficiency most desired?

A) When only a false positive might cause harm
B) When the condition is both serious and treatable, and a false positive and false negative are equally injurious
C) When the suspected medical condition is serious but not treatable, and a false positive can cause harm
D) When the suspected medical condition is serious and treatable, and a false positive does not have harmful consequences