Tubular sections are considered the most economical compression members because they possess several advantageous characteristics that make them ideal for resisting compressive loads. The correct answer, option 'D', states that tubes have high local buckling strength, more torsional resistance, and are subjected to less wind force than any other section. Let's discuss each of these factors in detail:

1. High Local Buckling Strength:
Tubular sections have a high resistance to local buckling due to their circular shape. The curvature of the tube provides a continuous and uninterrupted load path, which helps to distribute the compressive forces evenly throughout the section. This results in a higher buckling strength compared to other structural shapes, such as I-sections or angles.

2. More Torsional Resistance:
Tubular sections exhibit excellent torsional resistance due to their closed cross-sectional shape. The circular geometry of tubes helps to distribute and resist torsional loads effectively. This is particularly advantageous in situations where the compression members are subjected to both axial and torsional loads, such as in transmission towers or offshore structures.

3. Less Wind Force:
Tubular sections also experience less wind force compared to other section shapes. The streamlined shape of tubes reduces the wind pressure and drag coefficient, resulting in lower wind forces acting on the structure. This is especially important for tall structures, where wind loads can have a significant impact on the overall stability and design of the compression members.

In summary, tubular sections are the most economical compression members due to their high local buckling strength, superior torsional resistance, and reduced wind forces. These characteristics make tubes highly efficient in carrying compressive loads, resulting in cost-effective designs for various structural applications.