Consider these following sentences and choose the correct ones. I. Each gene contains a specific promoter region and a leader sequence for guiding the beginning of transcription. II. Only one strand of DNA, called template strand is copied by RNA polymerase this strand runs in $3^{\prime} \rightarrow 5^{\prime}$ direction. III. RNA polymerase adds complementary nucleotides forming single strand $m$ RNA in $3^{\prime} \rightarrow 5^{\prime}$ direction. IV. Section of DNA that has been transcribed is rewound into its original configuration.

• A

  II, III and IV
• B

  II and IV
• C

  I, II and IV
• Correct answer
  D

  I, II,III and IV

Hence, the correct answer is option: 'D'.