Explanation:

- A "Needle" is a tool used for "Hemming", which is a sewing technique.

- This suggests a relationship where a tool is associated with its function or purpose.

- Pen

- A "Pen" is a tool used for the act of writing.

- Writing is the primary function of a pen.

- Option 1: Paper

- Paper is a medium where writing occurs, not directly related as a tool-function match.

- Option 2: Ink

- Ink is an essential component for a pen's function, but not the act itself.

- Option 3: Nib

- The nib is part of a pen that helps in writing, a component not function.

- Option 4: Writing

- Writing is the action performed with a pen, similar to hemming with a needle.

- It matches the tool to its function.