Which is biotic ?
a: wind
b: iron gate
c: sunlight
d: dead leaf

Out of all of them, the dead leaf sounds like it'd be biotic.

Explanation:

The wind, the gate and sunlight are all abiotic examples.

Dead leaf

The other things are arn't alive nor at one piont alive. The leaf on the other hand came from a tree, I living breathing thing. But the Sun, Wind, and Iron gate are not alive and were never alive nor will thaey ever be alive.

So the anser is Dead leaf

I hope this helps!

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