How do I stretch a container in flutter so that it occupies the remaining screen?

Question

I'm trying to maximize the screen as there is an unused white gap at the bottom (below the green bar which is the countdown/timer for the qn) :

Code:

    final quizBottomContentText = Container(
      width: MediaQuery.of(context).size.width,
      padding: EdgeInsets.only(left:30.0, right:30.0, top: 30.0, bottom: 30),
      child: Text(
        questions[questionNum].title,
        style: TextStyle(fontSize: 18.0),
      )
    );

    final quizOptions = Container(
      width: MediaQuery.of(context).size.width,
      padding: EdgeInsets.only(left: 40.0, right:40.0, bottom: 40.0),
      child: Center(
        child: Column(
                  children: questions[questionNum].options.map<Widget>(
                    (option) =>  SimpleRoundButton(
                        backgroundColor: Color.fromRGBO(58, 66, 86, 1.0),
                        buttonText: Text(option, 
                            style: TextStyle(
                                color: Colors.white
                            ),
                        ),
                        textColor: Colors.white,
                        onPressed: (){},
                    ),
              ).toList(),
        )
      )
    );

    final countdown = CountdownWidget(
          width: MediaQuery.of(context).size.width,
          duration: 20,
          triviaState: triviaState,
        );

    final quizBottomContent = Container(
     width: MediaQuery.of(context).size.width,
      child: Column(
        children: <Widget>[quizBottomContentText, quizOptions, countdown], // need countdown 
      ),
    ); 

I've been trying the following but I cant seem to get what I want:

 // Column for quizBottomContent
 mainAxisAlignment: MainAxisAlignment.spaceBetween,

Solution

Wrap your bottom widget in Column inside Expanded (I think, this is what you want)