Final answer:
The most volume in a hairstyle is achieved with high density and coarse texture, as the large number of thick hair strands creates a fuller appearance.
Step-by-step explanation:
The combination that would create the most volume in a hairstyle is high density and coarse texture. High density means that there are more hairs per square inch on the scalp, which naturally creates more volume. Coarse hair has a thicker strand diameter, which stands out from the scalp more than fine hair, further contributing to the perceived volume. Hence, a person with high hair density and coarse-textured hair would have the most voluminous hairstyle.