Final answer:
Absolute value functions have a vertex that can be a minimum or maximum, a vertical axis of symmetry through the vertex, and their domain is all real numbers. The range depends on whether the vertex is a minimum (range: y ≥ vertex's y-coordinate) or maximum (range: y ≤ vertex's y-coordinate).
Step-by-step explanation:
The key features of an absolute value function include the vertex, which is the turning point and can be either a minimum or maximum point, the axis of symmetry, which is always a vertical line passing through the vertex, and the domain and range.
For an absolute value function, the domain is all real numbers, and the range is all real numbers greater than or equal to the y-coordinate of the vertex if the vertex is a minimum, or all real numbers less than or equal to the y-coordinate of the vertex if it is a maximum.
Incorrect options include: a horizontal axis of symmetry which is not a characteristic of an absolute value function; a vertex that intersects with the x-axis, which is not a typical feature unless the vertex is at the origin; a diagonal axis of symmetry, which does not apply to absolute value functions; and no axis of symmetry, which contradicts the nature of absolute value graphs that are mirrored across the axis of symmetry. Absolute value functions cannot have a maximum point as the vertex without being reflected over the x-axis, which would still imply vertical symmetry.