The distance of centroid of a semi-circular lamina of radius R form the straight edge of this semi-circular lamina will be:

• A. \(\frac{{8R}}{{3\pi }}\)
• B. \(\frac{{4R}}{{3\pi }}\)
• C. \(\frac{{2R}}{{3\pi }}\)
• D. \(\frac{R}{{3\pi }}\)