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Identity function I: A → A is:

AI(x) = 0
BRandom
CI(x) = x for all x
DI(x) = 1
Answer & Solution
Correct answer: C. I(x) = x for all x
I(x) = x. Maps every element to itself. Both injective and surjective. **Composition:** f ∘ I = I ∘ f = f. Identity of composition.
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