She clearly did not know what to say in response.

Young, already aware of what to do, said nothing in response.

She tried to find something to say in response, and couldn't think of anything.

His silence told her more than anything he might have said in response.

It was hard to think what to say in response.

If she said something in response, none could hear it.

There didn't seem to be anything to say in response.

I'm not sure what I tried to say in response.

I would want to ask her, What did you say in response?

He was not certain what the Council would say in response.