The answer is C. Needle.
A screw is a thin, cylindrical piece of metal with a spiral groove on its outside that is used to fasten two or more pieces of material together. A hammer is a tool used to drive nails or other objects into wood or other materials. A pin is a small, thin piece of metal or wood with a pointed end, used for fastening or attaching things together. A nail is a thin, pointed piece of metal with a head, used for fastening things together.
A needle is a thin, sharp piece of metal with a pointed end, used for sewing or piercing things. It is different from the other options because it is the only one that is not used to fasten things together.