The answer to the question “Typist : Typewriter :: Writer : ?” is Pen.
A typist is a person who uses a typewriter to write text. A typewriter is a machine that uses keys to print letters, numbers, and symbols on paper. A writer is a person who writes text, usually for publication. A pen is a tool that is used to write or draw.
The relationship between a typist and a typewriter is similar to the relationship between a writer and a pen. A typist uses a typewriter to write text, just as a writer uses a pen to write text. Both a typewriter and a pen are tools that are used to write text.
The other options are not as closely related to the relationship between a typist and a typewriter. A book is a collection of written or printed sheets of paper or parchment bound together to form a volume. Paper is a thin, flexible material that is used for writing, printing, and packaging. A script is a written or printed version of a play, film, or other performance.
While a book, paper, or script can be used by a writer, they are not as closely related to the act of writing as a pen is. A pen is a tool that is specifically designed for writing, while a book, paper, or script are not.