Which of the following statements are correct with reference to a transcription unit ?
A. A transcription unit in DNA is defined primarily by three regions : promoter, structural gene and terminator.
B. The promoter is said to be located towards the \(5^{\prime}\)-end of the structural gene.
C. The promoter is a DNA sequence that provides binding site for RNA polymerase.
D. The promoter defines the template and coding strands.
E. The terminator is located towards the \(3^{\prime}\)-end of the coding strand and it defines the end of the process of transcription.
Choose the correct answer from the options given below :

(D) A, B, C, D and E
Statement A is correct as a transcription unit in DNA is primarily defined by three regions: a promoter, a structural gene, and a terminator.
Statement B is correct because the promoter is located towards the \(5^{\prime}\)-end (upstream) of the structural gene, with reference to the polarity of the coding strand.
Statement C is correct as the promoter is a specific DNA sequence that provides a binding site for RNA polymerase to initiate transcription.
Statement D is correct because the presence and position of the promoter in a transcription unit define which strand acts as the template and which as the coding strand.
Statement E is correct as the terminator is located towards the \(3 ^{\prime}\)-end (downstream) of the coding strand and marks the end of the transcription process.
Since all statements A, B, C, D, and E are correct, the correct option includes all of them.