Final answer:
Mary Lou Williams was a pianist and composer who worked in various jazz styles and had a long, influential career, but she did not play the trumpet.
Step-by-step explanation:
All of the following are true of Mary Lou Williams EXCEPT: c) She played the trumpet. While Mary Lou Williams was indeed a pianist and she composed in various jazz styles, she did not play the trumpet. Williams is renowned for her prowess on the piano and for having a long and influential career in the jazz music industry. She was an exceptional composer and her ability to work within a variety of jazz styles is well-documented. Her career spanned several decades and she worked with many other famous jazz musicians, leaving an indelible mark on the genre.