Final answer:
The faces of fashion models are particularly pleasing because of their symmetry, as it signifies better overall health and genetic fitness.
Step-by-step explanation:
The correct answer is d) Symmetry. The faces of fashion models are believed to be particularly pleasing because of their symmetry. Symmetry refers to a balanced arrangement of body parts, where the left and right sides of the face are mirror images of each other.
Faces with greater symmetry are perceived as more attractive because asymmetry can be an indication of genetic or developmental abnormalities. Studies have shown that people generally find faces with more symmetrical features to be more attractive and appealing.
For example, research has demonstrated that people tend to rate faces with high facial symmetry as more beautiful or attractive. In the field of biology, symmetry is considered an important factor in mate selection, as it signifies better overall health and genetic fitness.