"Thou loosest labour
As easy may'st thou the in trenchant air
With thy keen sword impress,..."

Based on William Shakespeare's Macbeth, the confidence above derives from the fact that

• A.the air cannot be cut
• B.it is futile to cut the air with a sword
• C.no man born of a woman can hurt Macbeth
• D.Macduff wastes his efforts fighting Macbeth
• E.