Final answer:
To obtain and erect an image using a concave mirror of focal length 10 cm, the range of the object from the mirror should be 20 cm. The nature of the image is real and inverted.
Step-by-step explanation:
In order to determine the range of the object, we need to use the mirror formula: 1/f = 1/do + 1/di, where f is the focal length, do is the object distance, and di is the image distance. Since the mirror is concave, the focal length is positive, so f = 10 cm.
If the image is to be erect and real, the image distance di must also be positive. Therefore, we can substitute the given values into the mirror formula to solve for do: 1/10 = 1/do + 1/10. Solving for do, we find that do is equal to 20 cm.
Therefore, the correct answer is a. Range = 20 cm, Real and Inverted.