What is the primary difference between pre-mRNA and mature mRNA?

• A. Pre-mRNA is found in the cytoplasm, while mature mRNA is found in the nucleus.
• B. Mature mRNA is transcribed from DNA, while pre-mRNA is translated into protein.
• C. Mature mRNA contains introns, while pre-mRNA does not.
• D. Pre-mRNA contains introns, while mature mRNA does not.

Answer: (D)