Which of the following colors appears at the base of an agouti hair shaft?

In an agouti hair shaft, dark slate is the correct color that appears at the base. Agouti fur has a unique characteristic where individual hairs are banded with multiple colors, creating a blend effect. The base of the agouti hair is typically darker, and dark slate is a common representation of that base color. This darker base contributes to the overall appearance of the agouti pattern, allowing for the lighter tips to visually contrast against it.

Other colors listed do not accurately represent the base of an agouti hair shaft. White typically describes a lack of color or reflects light differently and does not contribute to the agouti's distinctive coloration. Black, while it may appear in various breeds, is not the foundational color for the agouti pattern itself. Brown also does not accurately depict the base of an agouti hair; instead, it might describe other types of fur or patterns that are not specific to agouti. Understanding the specific characteristics of fur color patterns helps in identifying correct coloration in rabbit breeds.