ANS:E - All the above.

All the above. Explanation:

1. Lateral reinforcement in R.C.C. columns is provided to prevent the longitudinal reinforcement from buckling: Lateral reinforcement, often in the form of stirrups or ties, helps confine the longitudinal bars in columns, preventing them from buckling under compressive forces. This enhances the column's load-carrying capacity and ductility.
2. Lateral reinforcement prevents the shearing of concrete on diagonal plane: Lateral reinforcement also helps resist shear forces by providing additional confinement to the concrete within the column. This prevents the concrete from shearing along diagonal planes, improving the column's resistance to lateral loads and enhancing its overall stability.
3. Lateral reinforcement stops breaking away of concrete cover, due to buckling: In addition to preventing buckling of longitudinal bars, lateral reinforcement helps maintain the integrity of the concrete cover surrounding the reinforcement. This reduces the risk of spalling or breaking away of concrete due to buckling forces, ensuring the durability and protective function of the concrete cover.
4. Lateral reinforcement in R.C.C. columns is kept not less than 5 mm diameter: The diameter of lateral reinforcement is typically specified to ensure adequate strength and stiffness to resist applied forces. While 5 mm is a common minimum diameter for lateral reinforcement in columns, the actual diameter may vary depending on design requirements, column dimensions, and loading conditions. However, it is essential to ensure that the lateral reinforcement provided meets the specified standards and is sufficient to fulfill its intended functions effectively.