What are the values of dimensional accuracy obtained while machining spherical surfaces?

• A. ¬¨¬®¬¨¬± 1 ¬¨¬®¬¨¬µm
• B. ¬¨¬®¬¨¬± 3 ¬¨¬®¬¨¬µm
• C. ¬¨¬®¬¨¬± 5 ¬¨¬®¬¨¬µm
• D. ¬¨¬®¬¨¬± 7 ¬¨¬®¬¨¬µm