Question: What season was the mother promoted to a main character on how i met your mother and how many episodes did that season have?
Sentence (from "How I Met Your Mother (season 9)"): The ninth and final season of "How I Met Your Mother", an American sitcom created by Carter Bays and Craig Thomas, premiered on CBS on September 23, 2013, with two episodes, and concluded on March 31, 2014.
Relevant evidence: No