Concept:Image sharpness in a pinhole camera depends on the size of the pinhole aperture.Explanation:A larger pinhole allows more light to enter, which increases brightness.However, the wider opening causes light rays from a single point of the object to spread over a larger area on the screen.This overlapping of light spreads the image and makes it appear less sharp or blurred.Therefore, a less sharply defined image occurs when the pinhole is larger.Answer:A. pin-hole is larger