The inside clearance of the sampler is ________

• A. \(\frac{D_3-D_1}{D_1} ×100 \)
• B. \(\frac{D_3+D_1}{D_1} ×100\)
• C. \(\frac{D_3-D_1}{D_3} \)
• D. \(\frac{D_3-D_1}{2D_1} ×100\)