Concept:CAD helps designers create and visualise product designs, especially 3D models, on a computer.
Explanation:Computer Aided Design makes it easy to produce, rotate, resize and test digital 3D models before actual production.
Designers can simulate real-world performance and correct faults quickly.
This saves effort and supports better manufacturing planning.
The best reason from the options is that 3D designs are easily produced with CAD.
Option B is not the best because CAD directly shortens the design stage rather than the physical manufacturing time itself.
Similarly, CAD requires enough system resources, and trained designers are still needed.
Therefore, the correct choice is the one about producing three-dimensional designs.
Answer:D. 3D designs are easily produced with it.