Which among the following is/are the correct assumptions made in the torsion formula?A. Material of the shaft is uniform throughoutB. Twist along the shaft is uniformC. Plane sections before twisting remain plane after twistingC. Circular Sections before twisting remain circular even after twisting.

• A. A, B, C and D
• B. C and D
• C. A, B and C
• D. B and D