Here's why:

* DNA is located in the nucleus: The genetic information needed for transcription is stored in DNA, which resides within the nucleus.

* RNA polymerase is found in the nucleus: The enzyme responsible for transcribing DNA into RNA, RNA polymerase, is located in the nucleus.

* mRNA needs to move to the cytoplasm: The messenger RNA (mRNA) created during transcription must travel to the cytoplasm for translation, making the nucleus the ideal location for the process.