A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well-illuminated red building as the object, which of the following correctly describes the features of the image formed?

The ray diagram of a distant object kept in front of a concave mirror is as shown in the diagram above. (Note: A diagram would ideally be included here to visually represent the situation. Since I cannot create images, a description will suffice). Rays from the object, which is at a large distance, will be approximately parallel and will converge near the focal point (F) of the concave mirror after reflection. The image formed will be real, inverted, and diminished. The color of the image will be the same as the object, which is red. Hence, the correct answer is "Real, inverted, diminished image in red shade".