D. All of the above.
Explanation:
Philosophy is an activity along with A group of writings and A collection of theories. I'm writing this all out because it said I had to write more.
Ragtime is a composed music essentially for piano. Ragtime is musical style that is multi-themed. Its key characteristic is simple syncopation or “ragged” rhythm which was rarely complex. Ragtime doesn’t improvise but the machine-like, cheerful music is a built-in device for improvisation.
