How can you cut an apple with this blunt knife?

Answer: Option B

Blunt : (of a cutting implement) not having a sharp edge or point.
Pointed : having a sharpened or tapered tip or end.
Sharpened : make or become sharp or sharper.
Polished : make the surface of (something) smooth and shiny by rubbing it.
Filed : place (a document) in a cabinet, box, or folder in a particular order.

Antonym of Blunt is Sharpened