Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Wolfgang Amadeus Mozart’s was the only-surviving son of Leopold and Maria Pertl Mozart. Leopold was a successful composer, violinist, and assistant concert master at the Salzburg court. Wolfgang's mother, a constantly ill housewife, was born to a middle class family of local community leaders. His only sister was Maria Anna. With their father’s encouragement and guidance, they both were introduced to music at an early age. Leopold started Anna on keyboard when she was seven, as three-year old Wolfgang looked on. Mimicking her playing, Wolfgang quickly began to show a strong understanding of chords, tonality, and tempo. Soon, he too was being tutored by his father.

Leopold was a devoted and task-oriented teacher to both his children. He made the lessons fun, but also insisted on a strong work ethic and perfection. Fortunately, both children excelled well in these areas. Recognising their special talents, Leopold devoted much of his time to their education in music as well as other subjects. Wolfgang soon showed signs of excelling beyond his father's teachings with an early composition at age five and demonstrating outstanding ability on harpsichord and the violin. He would soon go on to play the piano, organ and viola.

The word “outstanding" in the passage is closest in meaning to ____.