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React Quiz Practice
Active Recall Drill Session
← Exit Session
Question 1 of 1
medium
React
Why is using the array index as a list's `key` risky?
A
It causes a compile error
B
It's fine in every case, no risk at all
C
If the list can reorder, filter, or have items inserted/removed, React can incorrectly match old state/DOM to the wrong item, since the index no longer reliably identifies the SAME item across renders
D
Index keys are slower to compute than random keys
Check Answer