Answer : 2. "Charlie and the Chocolate Factory"
Explanation :

1. Willy Wonka is a fictional character from the children's storybook 'Charlie and the Chocolate Factory'.

2. This book was written by Roald Dahl and first published in 1964 in the United States of America.

3. The character of Willy Wonka has also been featured in many movies and TV shows. The most famous portrayal was by Gene Wilder in the 1971 film 'Willy Wonka and the Chocolate Factory'.

4. The character of Willy Wonka has been very popular among children. He is often seen as a mischievous and funny person, but he is also good at heart. They love children and want to keep them happy always.