What type of brush is thin, made of nylon, and used for sectioning with a tail and narrow row of bristles?

The correct answer is the teasing brush, which is specifically designed for creating volume and texture in hairstyles. Teasing brushes have a thin profile and are made with nylon bristles that are closely packed, allowing for precise control when sectioning and teasing the hair. The tail of the brush is particularly useful for parting the hair into smaller sections, which is essential for effective teasing techniques. This brush helps to lift the hair at the roots, creating that desired fullness and volume that many hairstyles require.

The classic styling brush generally has a broader design suited for smoothing and finishing styles, while the grooming brush is typically used for detangling and adding shine, making them less suited for the specific task of teasing. The round brush is used primarily in blow-drying techniques to create curls and waves, which is also not its intended use for sectioning or teasing. Therefore, the teasing brush is the most appropriate choice for the described attributes and functionality.