With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: Heavy metal poisoning is highly likely if fish-oil supplements are overconsumed in extreme amounts, however, because heavy metals (mercury, lead, nickel, arsenic, and cadmium) that selectively bind with protein in the fish flesh can leach into the fish oil.
text_B: Since heavy-metal toxicity is something that occurs slowly over a lifetime, in even the worst case scenario, could fish-oil supplements still be taken by the elderly without undue worry?
YES.