The correct answer is B. Make. So the complete phrase is "Children often make up imaginative stories.
Explanation
"Makeup" is a verb that refers to the action of inventing something; is an action that involves the imagination and creativity to innovate. Additionally, this action is very related to children because in the early years, people tend to ignore reality and create their world. According to the above, the correct answer is B.
"During the shop’s peak hours – from eight in the evening till around midnight – one could hardly hear oneself talk because of the boisterous chatters that went on."
