Answer:
The following statement: "In 1848, rioting in Berlin forced the Prussian king Frederick William IV to promise a constitution" is true.
Step-by-step explanation:
In 1848 a set of riots broke in the city of Berlin as part of what is known as the "March Revolution" of 1848 that broke out in many European countries that were fuelled by the popular discontent of the citizens with the autocratic political structures of most of the European governments. In Prussia, king Frederick William who has traditionally been opposed to liberal principles, surprised everyone when, pressured by the riots and escalating violence, allowed for elections to be held in order to elect a Prussian and German assembly. He also promised to his citizens the establishment of a constitution which was one of the main reasons for the riots to happen.