"She placed the keys here."

The correct answer is Option (3) → Adverb of Place

An adverb is a word that tells how, when, where or how much something happens. It can also describe an adjective or another adverb, for example she sings sweetly, very hot.

In this sentence, here tells where she placed the keys.

Option	What it tells	Example
(1) Adverb of Reason	why something happens	The milk had gone sour and therefore we threw it away.
(2) Adverb of Time	when something happens: “here” names a place, not a time	I will do my homework later.
(3) Adverb of Place (answer)	answers the question where? (here, there, inside, outside, up, down)	Please sit here next to me.
(4) Adverb of Manner	how an action is done	She placed the glass vase gently on the table.