17. In the Key of C, the 15, 4th, and 5th notes of the C Major scales are the primary chords. Which of the following are the primary chords of C Major? a. C major, F major & G major c. F major, Bb major & C major b. G major, C major & D Major d. D major, G major & A major 18. For the C major, which is called as the Tonic chord? a. Do c. La b. Fa d. So 19. For the C major, which is called as the Sub-dominant chord? a. Do c. La b. Fa d. So 20. For the C major, which is called as the Dominant chord? a. Do c. La b. Fa d. So​