Concept:A good electric cell should be efficient, durable, safe, and economical in use.
Explanation:A good electric cell is expected to have a minimum polarization effect to maintain steady current.
It should have a long life so it can serve for a longer period.
It should use cheap and safe electrolytes for affordability and safety.
Being costly and dangerous is not a desirable feature of a good cell.
Therefore, the option that is not a characteristic of a good electric cell is the one referring to cost and danger.
Answer:D. Cost and dangerous of the cell