Which of the following option is true for truncation?

• A. Thread can be tranculated at crest only
• B. Thread can be tranculatd at root only
• C. Thread can be tranculated at crest and root both
• D. Thread can‚Äö√Ñ√∂‚àö√ë‚àö¬•t be tranculated at crest and root both