Answer:
It will not dissolve. More crystals will separate from the solution.
Step-by-step explanation:
If you add a crystal of ammonium nitrate to a supersaturated solution of the solute, it will not dissolve.
Instead, it will act as a "seed" on which more ammonium nitrate crystals will form.
They will separate from the solution as long, colourless, needle-like crystals until the solution is no longer supersaturated.
