According to the passage, a "white lie" seems to be a lie ______

A．they wish they were somewhere else
B．the nose is sensitive to physical changes caused by lying
C．they want to cover their mouths
D．they are trying to stop themselves from telling lies

A．his blood pressure increases measurably
B．he looks very serious
C．he tends to make some small changes in his behavior
D．he uses his unconscious mind