Which word is correctly used in the sentence?

you're probably wondering __ pounding on your door.

who's
whose

idk

explanation:

i believe it would be the first one the importance of internet safety

explanation:

because now and days kids don't know what the can find on the internet they can find dark web, 4 chan ect. if we don't teach them internet safety anything can happen.

(don't search up,dark web,4 chan u have been warned)

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