What does the term "tonal answer" refer to in a fugue?

In the context of a fugue, the term "tonal answer" refers to the way the subject or theme is presented after its initial statement, specifically indicating that the theme is transposed to the dominant key rather than presented exactly as it was first introduced. This transposition allows the fugue to create a sense of contrast and development while maintaining a connection to the original material.

When the theme is transposed to the dominant key, it retains some of the original melodic content but may adjust certain pitches to fit better into that key context, creating a sense of tonal unity while also expanding the harmonic framework of the fugue. This technique is crucial in the development of the fugue as it provides opportunities for further variation and exploration of the thematic material in different keys.

The other choices reflect different concepts that do not align with the definition of a tonal answer; repeating the theme in the tonic key does not incorporate transposition, composing the theme in a minor key does not address the concept of a tonal answer specifically, and altering the rhythm of the theme focuses on rhythmic variation, which is a separate aspect of composition in fugues.