Question on protein synthesis?

Think of DNA as the original blueprint and mRNA as a copy of that blueprint. The DNA, which is in the nucleus, is WAY too valuable to send out to be translated so the body copies it into mRNA (m because it is the messenger). This conversion of DNA into mRNA is known as transcription and it happens in the nucleus where the DNA remains safe (wouldn't want to lose or damage the original blueprint). Once the messenger is made (mRNA) it LEAVES the nucleus and is translated (the message is decoded) at the ribosome. The ribosomes are found in the cytoplasm (either attached to the ER or free floating). This "decoding" of mRNA into a protein is known as translation (like translating one language into another). Now read the question and answers again. You realize that the correct answer is D. Hope this helped.