Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Input: [header] How to play bassline when playing the piano [title] Find the key and accompanying chords. [step] Determine which key the piece is in, and learn the basic chords for each key signature. In a major key, the one, four, and five chords are always major, and together they make a common chord progression. <sep> (A) [substeps] Alternatively, you can find chords tuner, jokey, or syncopated. This is specific to the piece as well as to the melody. (B) Make your way down the keyboard until you find the four chords for each key. [substeps] If your chord is in, play the note progression key, then the chords numerical row with the two ascending steps. (C) For example, in the key of c major, you can play the c major, f major, and g major chords. [title] Play the root of each chord with your left hand. (D) In a minor key, there's a four-chord pattern that you can vary. [substeps] Note that if you are playing the keyboard at all, you may notice that you shuffle each chord in the same order.
Output:
C