Detailed Instructions: 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.
See one example below:
Problem: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
Solution: who has the maximum number of followers on instagram
Explanation: The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

Problem: The Battle of Vimy Ridge was a military engagement fought primarily as part of the Battle of Arras, in the Nord-Pas-de-Calais region of France, during the First World War. The main combatants were the Canadian Corps, of four divisions, against three divisions of the German Sixth Army. The battle, which took place from 9 to 12 April 1917, was part of the opening phase of the British-led Battle of Arras, a diversionary attack for the French Nivelle Offensive.
Solution:
when did the battle of vimy ridge start