6. Which of the following descriptions about defective urea cycle is wrong? (A) The level of ammonia in the blood will decline, causing hypoammonemia, (B) Ammonia can enter the brain, inhibiting the TCA cycle and resulting in brain dysfunction, (C) this problem may arise because of damage to the liver, (D) this problem can be caused by mutations in carbamoy1 phosphate synthetase, (E) none of the above. LINE