A double-stranded DNA fragment with $12 \times 10^3$ nucleotides is transcribed and then translated to form one polypeptide. What is the greatest possible number of amino acids in this polypeptide?
- A$6 \times 10^3$
- B$4 \times 10^3$
- C$2 \times 10^3$
- D$1 \times 10^3$