What to do about the person who MUST answer every question

Some people are super extroverted. 
Few of them reside in churches. 
But they do exist.

And some people are super-charged bible study extroverts.

They feel the need to answer every question... Usually first.
They have an innate drive to add a comment... Even if it occurs prior to fully engaging their brain.

I've been in bible studies with these people.
I've lead bible studies with these people.
I've overseen youth ministries which have included, both as participants and leaders, these people.

At times they are wonderful.
They stimulate discussion.
They keep the study progressing.
They, usually, far exceede silence.

But, they can also, unhelpfully, dominate.
They can be a distraction.
They can steal the train of thought of others or deprive them of feeling that they need to contribute.

So, what do you do with the always-answering extrovert?

As the youth minister, if a leader was dominating their group then I just asked them to slow down. Count to ten before you answer. Intentionally wait for someone else to respond first for every second question. 

As a leader, if a participant is overpowering others giving their input, then there's a few simple things you can do. 

First, you can split people into pairs and ask them to talk about the question, then, intentionally, don't ask for mr/mrs talkalot pairing to respond first.

Second, similar to the first option, you could specifically ask for an induvidual to respond first, or a type of induvidual (such as gender or life stage).

But, always remember, any group should be welcome and enclusive for all. Even those who love to chatter away.