This is the 5225th most frequent Polish word.
reakcją
"Reakcją" in English means "reaction."
In this sentence, 'reakcją' is used as a noun in instrumental case to describe the manner of responding to the event.
Jej reakcją na niespodziankę była radość.
Her reaction to the surprise was joy.
Here, 'reakcją' again serves as a noun in instrumental case, emphasizing the outcome or response to the stimulus.
Reakcją na pytanie było milczenie.
The reaction to the question was silence.
In this context, 'reakcją' is used to indicate the type of response or expression one might display in response to a situation.