1. The problem asks to identify the shaded part of a circle formed by two points A and B on the circumference and the center O, with the angle at O marked as $\alpha$. 2. The shaded area is the region bounded by the two radii OA and OB and the arc AB. 3. This region is called a "sector" or "juring" in Indonesian, which is the area of a circle enclosed by two radii and the arc between them. 4. Other options: - Tembereng (segment) is the area bounded by a chord and the arc it subtends, not including the center. - Jari-jari (radius) is a line segment from the center to the circumference. - Diameter is a line segment passing through the center connecting two points on the circumference. 5. Since the shaded area includes the center and is bounded by two radii and the arc, the correct answer is b. Juring. Final answer: b. Juring