Which of the following terms describes playing slowly?

The term that accurately describes playing slowly is "rallentando." This musical directive indicates a gradual decrease in tempo, encouraging performers to slow down the pace of the music over a specified period. It's particularly useful in creating a feeling of tension or relaxation in a piece, allowing for expressiveness and emotional depth.

In contrast, other terms listed refer to different concepts in music. "Pianissimo" signifies playing very softly rather than at a slow pace. "Fine" is a term that marks the end of a section or piece, indicating no change in tempo, and "allegretto" denotes a moderately fast pace, which is not aligned with a slow performance. Understanding these distinctions is essential for interpreting and performing music accurately.