Before the late 20th century, drawings were usually made manually, but the widespread use of computers has now enabled the creation of drawings and designs using computer-aided design (CAD) programs. Modern CAD programs allow engineers to produce three-dimensional models, which can be used directly in the manufacture of the devices depicted. Based on the context, what is the given information, A, B, C, or D?
A、the late 20th century
B、computers
C、drawings and designs
D、manufacture of the devices