Which of the following treatments is primarily used to remove excess bulk from hair?

Texturizing is a specific technique used in hairstyling that focuses on altering the hair's structure to create shape and remove bulk. This method involves cutting the hair in a way that removes excess weight and volume while maintaining length. Texturizing can involve various techniques, such as using shears or specific cutting tools that allow for the removal of hair without drastically changing the overall length.

In contrast, layering adds dimension to the hairstyle by introducing different lengths, which can sometimes create the illusion of volume but does not specifically target the removal of bulk. Blow drying is a styling method that primarily focuses on drying the hair and achieving a certain shape or look, rather than modifying its volume. Conditioning is related to hair health and maintenance, aimed at improving texture and moisture but does not directly address hair bulk removal. Therefore, texturizing is the most appropriate choice for the goal of removing excess bulk from hair.