Final answer:
The ten-degree, cone-shaped area of vision straight ahead is referred to as foveal vision, which is responsible for sharp central vision due to the concentration of cones in the fovea.
Step-by-step explanation:
The ten-degree, cone-shaped area of vision straight ahead is known as foveal vision (A). The fovea is a small, central pit composed of closely packed cones in the eye and is responsible for sharp central vision, which is necessary for activities where visual detail is of primary importance, such as reading and driving. Cones are concentrated in the fovea and are better for bright light vision, while rods, located more peripherally in the retina, are more responsive to dim light and thus contribute to peripheral vision.