who's asking

(defensively) Used to ask a stranger asking a question to identify themselves

Japanese Meaning

誰が質問しているのか？という意味で、相手に自分の身元を明らかにさせようとする防御的な表現

Before I answer, who's asking?

答える前に、どちら様ですか？

Sense（1）

(defensively) Used to ask a stranger asking a question to identify themselves

"Are you the owner of this vehicle?" / "Who's asking?"