In the following figure, the square represents accountants, the triangle represents artists, the circle represents planners, and the rectangle represents men. Which set of letters represents men who are artists?

Let's track the relevant intersection fields:
1. Men: Represented by the horizontal rectangle.
2. Artists: Represented by the triangle.
3. We need to find the letters that lie simultaneously inside both the rectangle (men) and the triangle (artists).
4. Looking closely at the intersection of the triangle and the rectangle, the letters common to both regions are A and B.