Final answer:
Foil Highlights is the hair coloring technique that involves coloring selected strands of hair. Perming, by contrast, is a process that chemically alters hair texture to curl or wave it, and is not related to the alternation of hair color strands.
Step-by-step explanation:
The technique referred to in the question, which involves alternating selected strands of hair within a section, is known as c) Foil Highlights. This method entails coloring certain strands of hair, typically by separating them using foil for precision and to isolate them from the rest of the hair during the coloring process. In contrast, Balayage is a freehand technique where color is painted onto the hair to create a graduated, natural-looking effect. Ombre is where the hair transitions from a darker shade at the roots to a lighter one at the ends. Perming, on the other hand, is not a color technique but a textural one, which chemically alters the structure of hair to produce curls or waves.
A permanent hairstyle, commonly called a perm, can be achieved using thermal or chemical means and may last several months. During a perm, chemicals are applied to the hair, which is then shaped around forms and set to produce the desired hairstyle. This chemical process can also be used to straighten or relax hair, with the difference being in the final texture (curled or flattened).