Answer:
B. Determined.
Step-by-step explanation:
Determination is the key quality that is required in the process of learning. It is the ability that assists an individual to set goals of life and initiate them effectively.
It is the belief that keeps an individual hooked to their aspirations without giving up on the circumstances. Similarly, in this passage, Trey reflects this ability to learn as despite failures he keeps on trying which depicts the firmness of his belief. He has made his choice to struggle with the musical notes and not giving up to failures and finally turns victorious as his mother says "that sounds good". Thus, his determination motivated his belief and finally, he could learn.