Which of the following instruments plays one octave higher than a piano?

The piccolo is a woodwind instrument that plays one octave higher than the standard concert pitch, which includes the range of the piano. The piccolo is tuned in C, meaning that when it plays a written C, it sounds one octave higher than where it is written. This characteristic makes it very distinct and piercing in sound, often used for its bright tonal qualities in orchestral and chamber music settings.

In contrast, the piano, cello, and trumpet do not share this specific relationship with the written pitch. The piano, being a versatile keyboard instrument, plays in a wide range that includes several octaves. The cello, a string instrument, has a much lower range than the piano and does not reach the higher octaves the piccolo does. The trumpet, while it can be a transposing instrument depending on its key (such as B♭ or C trumpet), typically sounds a tone lower than the written pitch, which does not place it one octave higher than the piano. Thus, the piccolo is the correct choice as it uniquely fulfills the condition of playing one octave higher than a piano.