Final answer:
A moveable guide that consists of a small amount of previously cut hair is known as a mobile design line. This type of design line is used in haircutting to create consistency and control in the cutting process.
Step-by-step explanation:
The correct answer is d. mobile. A moveable guide that consists of a small amount of previously cut hair is known as a mobile design line. This type of design line is used in haircutting to create consistency and control in the cutting process. It allows the stylist to reference the length and shape of the previously cut hair while working on the rest of the hair.