Final answer:
To adhere artificial eyelashes to the natural lash line, a special adhesive or glue is used, not mascara or eyeliner which serve different cosmetic purposes.
Step-by-step explanation:
The substance used to make artificial eyelashes adhere or stick to the natural lash line is a) glue. When applying artificial eyelashes, a special adhesive or glue is applied to the base of the false lashes. This glue is specially formulated to be safe for use around the delicate eye area and ensures that the false eyelashes stay in place until they are removed.
On the other hand, mascara is a cosmetic used to enhance the eyelashes. It comes in various forms such as liquid, powder, or cream. The primary purpose of mascara is to darken, thicken, lengthen, and define the eyelashes. Eyeliner is used to define the shape of the eyes and create aesthetic effects, but it does not have adhesive properties to attach false eyelashes. A primer might be used to prepare the eyelashes for mascara application but also does not serve as an adhesive.