Final answer:
In classical music, themes can contrast in various ways, but in the fourth movement of Eine Kleine Nachtmusik, none of the provided options accurately describe the contrast between themes as the composition typically does not have drastic changes in tonality, tempo, instrumentation, or meter within a single movement.
Step-by-step explanation:
When considering how theme 2 contrasts with theme 1 in the fourth movement of Eine Kleine Nachtmusik, it is important to look at the compositional techniques Mozart used. While this question seems to pertain to the structure of a musical composition, it should be noted that 'Eine Kleine Nachtmusik' doesn't have contrasting major and minor themes within a single movement, nor does it typically entail a change in instrumentation or meter within the themes of a single movement. However, for the sake of answering the student's question, here is a general way themes can contrast in classical music:
Themes may contrast in tonality, with one being in a major key and another in a minor key, although this is not applicable to Eine Kleine Nachtmusik's fourth movement.
Another point of contrast can be tempo; however, within a single movement, themes typically maintain the same tempo, with variations being more nuanced than a straight tempo change.
Different themes don't usually involve changes in the instruments; however, they may feature different instrumental voices or textures prominently.
Meter changes between themes within a single movement are rare in classical music, with consistency in meter being a common feature.
Given this information, none of the options provided, A through D, accurately describe a contrast between themes 1 and 2 in the fourth movement of Eine Kleine Nachtmusik.