instruction:
In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
question:
A Christmas tree is a decorated tree, usually an evergreen conifer such as spruce, pine, or fir or an artificial tree of similar appearance, associated with the celebration of Christmas. The modern Christmas tree was developed in medieval Livonia (present-day Estonia and Latvia) and early modern Germany, where devout Christians brought decorated trees into their homes. It acquired popularity beyond the Lutheran areas of Germany and the Baltic countries during the second half of the 19th century, at first among the upper classes.
answer:
when did decorations on the christmas tree began


question:
The seventh and final season of the American mystery drama television series Pretty Little Liars, based on the books of the same name by Sara Shepard, was renewed on June 10, 2014 for two additional seasons, making the show Freeform's longest running original series.
answer:
how many seasons pretty little liars will there be


question:
This doctrine was defined dogmatically at the First Ecumenical Council of the Vatican of 1869 -- 1870, but had been defended before that, existing already in medieval theology and being the majority opinion at the time of the Counter-Reformation.
answer:

when did the doctrine of papal infallibility begin