Which of the following is the first novel of Beryl Bainbridge?

The correct option is A Weekend with Claude.

To understand why this is the correct answer, let's look at the publishing history of Beryl Bainbridge's novels:
1. A Weekend with Claude was published in 1967. This was her first published novel, although she later revised it in 1981.
2. Harriet Said... was actually written before A Weekend with Claude (completed around 1958), but it was repeatedly rejected by publishers due to its controversial content. It was not published until 1972.
3. The Bottle Factory Outing was published in 1974.
4. Filthy Lucre was written when Bainbridge was only a teenager (around 1946) but remained unpublished for decades, eventually being released in 1986.

Therefore, based on the official publication dates, A Weekend with Claude (1967) is recognized as the first published novel of Beryl Bainbridge.