Function of hypo used in fixer is:: (A) Inactivates the carryover developing agent, (B) Dissolves and removes the unexposed silver halide, (C) Prevents damage to gelatin, (D) All of the above
Answer is B. An aqueous solution of ammonium thiosulfate (“hypo”) dissolves the unexposed silver halide grains. It forms stable, water-soluble complexes with silver ions, which diffuse from the emulsion. Excessive fixation (hours) results in a gradual loss of film density because the grains of silver slowly dissolve in the acetic acid of the fixing solution.
White and Pharoah's Oral  Radiology Principles and Interpretation 8th edition