Solve the following problem in a SQL language of your choice. Given three tables: Authors id name Books id author_id title published_date Sales id book_id date price (A) Find the total sales by author in October 2020. The result set should have two columns: author's name and their total sales. (B) For each author, return the title and published_date of their first book. The result set should have five columns: author's id, author's name, book's id, book's title, and book's published_date. (C) Find the name of the author who had the median amount of sales in the prior calendar month. Your query should return a single record