C

A 1.5 % glycine solution is a hypotonic, nonelectrolyte distension medium; most guidelines advise stopping hysteroscopic surgery only when the fluid deficit approaches 1 L, because larger volumes raise the risk of dilutional hyponatremia and pulmonary edema. A 500 mL deficit is well below this 1000 mL safety limit, so the operation can proceed with ongoing deficit monitoring rather than being halted or the medium changed or diuretics given [Deffieux 2013, PMID 24210234].