Physiology If a substance “X” has more renal clearance than the GFR, it means: A "X" is only being reabsorbed by the tubules B "X" is being secreted by the tubules C "X" is being secreted as well as reabsorbed by the tubules D "X" is neither secreted nor reabsorbed 💡 Explanation If a substance "X" has more renal clearance than the GFR, it means: ✓ Correct Answer: B. "X" is being secreted by the tubules