eukaryotes mRNA transcription

Which one of the following statements about mRNA transcription and processing in eukaryotes is incorrect?

1. A methylguanosine cap is added to the 5' end of each transcript.
2. All transcription occurs in the nucleus.
3. A string of adenosines are added to the 3' end of the primary transcript by the same RNA polymerase     that transcribed the rest of the transcript.
4. Mature mRNAs are exported out of the nucleus into the cytoplasm for translation.
5. A single primary transcript can be turned into one of several possible mature mRNAs.