Which of the following assumptions are correct for the lateral torsional buckling of an I-section beam?1. The beam is initially distorted2. Its behaviour is elastic3. It is loaded by equal and opposite end moments in the plane of the web

• A. 1 and 2 only
• B. 2 and 3 only
• C. 1 and 3 only
• D. 1, 2 and 3