Miryam Has Been Playing the Violin Since She Was a Child

Miryam has been playing the violin since she was a child. She loves violin and practices frequently. When she is 15, her teacher tells her that she is quite talented and he wants her to enter a major competition for which she must practice three hours a day. Though Miryam usually practices more than three hours, she suddenly finds that she enjoys playing less and has to force herself to practice. One theory of motivation would suggest that Miryam's sudden loss of interest could be due to reduced feelings of competence because:

A) she no longer feels that she is choosing to practice
B) she is afraid of not doing well at the competition
C) the competition is now more important than the music
D) playing has become work, not pleasure