Question

A mutation within a gene sequence changes the start codon to a stop codon. How will this mutation affect the transcription of this gene?

A. Gene transcription will not occur, because it is stopped at the start codon.
B. Gene transcription will proceed normally.
C. Gene transcription will occur but will be down-regulated.
D. Gene transcription is unpredictable, and we cannot infer what might happen.

I think the answer is A, just want some clarification if I am either right or wrong. Thank you!