Final answer:
The Symphony No. 40 in G Minor, K. 550 by Mozart does not include percussion instruments. The tempo remains constant between the first and second themes in the exposition. The bridge passage in the recapitulation repeats the exposition exactly.
Step-by-step explanation:
In Mozart's Symphony No. 40 in G Minor, K. 550, the instrument group that is NOT heard is d) Percussion. Although the symphony includes instruments from each of the other groups (brass, woodwinds, and strings), it does not include any percussion instruments like drums or cymbals.
In terms of tempo, the first and second themes in the exposition of the symphony remain consistent. Both themes are played at a constant tempo, so the answer is c) It remains constant.
The bridge passage in the recapitulation does not differ from the exposition in any of the ways listed. Instead, it continues the themes and key of the exposition. Therefore, the correct answer is d) It repeats the exposition exactly.