Explanation

Copying the genetic sequence from one DNA strand into a complementary RNA molecule (mRNA, tRNA, or rRNA) is transcription, catalysed by RNA polymerase — the first step of the central dogma (DNA → RNA → protein). Translation (A) is protein synthesis from mRNA at the ribosome, replication (C) is DNA-to-DNA copying, and mutation (D) is a change in sequence. Hence B.