Step 1: Recall the process of transcription.
Transcription is the synthesis of RNA using a DNA template.
Step 2: Identify the enzyme responsible.
In prokaryotes, transcription is carried out by
\[
\boxed{\text{RNA polymerase}.}
\]
This enzyme binds to the promoter region and synthesizes RNA in the
\[
5' \rightarrow 3'
\]
direction.
Hence,
\[
\boxed{\text{RNA polymerase}}
\]
is the correct answer.
Therefore,
\[
\boxed{(B)}
\]
is the correct answer.