If the diameter of longitudinal bars of a square column is 16 mm, the diameter of lateral ties should not be less than A. 4 mm B. 5 mm C. 6 mm D. 8 mm

The correct answer is C. 6 mm.

The diameter of lateral ties should not be less than 0.35 times the diameter of the longitudinal bars. In this case, the diameter of the longitudinal bars is 16 mm, so the diameter of the lateral ties should not be less than 0.35 * 16 = 5.6 mm. The nearest standard size of lateral tie is 6 mm.

Option A is incorrect because the diameter of the lateral ties should not be less than 0.35 times the diameter of the longitudinal bars.

Option B is incorrect because the diameter of the lateral ties should not be less than 0.35 times the diameter of the longitudinal bars.

Option D is incorrect because the diameter of the lateral ties should not be less than 0.35 times the diameter of the longitudinal bars.