Based on the answers provided, the following corrections need to be made to the 3D object:

1. Change the shape of the object from a ring to a crescent. The object should resemble a curved "C" or a sickle to accurately represent a crescent shape.
2. Extrude the crescent sketch to give it a 3D form. Ensure that the extrusion maintains the crescent shape and does not form a complete ring.