Which instrument's range extends from E3 to C7?

The clarinet's range extending from E3 to C7 is due to its design and the acoustics of its construction, which allows it to cover a wide span of pitches. The instrument is a single-reed woodwind, and its key system enables advanced players to access higher notes while maintaining a robust low register. The clarinet's versatility makes it a key player in various musical genres, from orchestral to jazz.

In contrast, the other instruments mentioned have different ranges. The saxophone typically ranges from B♭3 to F♯7 depending on its type (alto, tenor, etc.), while the trumpet generally spans from F#3 to D6. The flute is known for its range from C4 to C7, offering a bright, clear sound that covers a different set of pitches than the clarinet. These differences in range and timbre highlight the unique characteristics and roles each instrument plays in musical settings.