The economical range of spacing of roof trusses is:

• A. \(\frac{1}{2}{\rm{\;to}}\frac{1}{3}{\rm{\;}}\)of span
• B. \(\frac{1}{2}{\rm{\;to}}\frac{1}{4}\)of span
• C. \(\frac{1}{4}{\rm{\;to}}\frac{1}{6}\)of span
• D. \(\frac{1}{3}{\rm{\;to}}\frac{1}{5}\)of span