A Scientist Obtains the DNA Sequence Datafor a Bacterial Plasmid

A scientist obtains the DNA sequence datafor a bacterial plasmid. The data includes As, Ts, and Gs, but no Cs.  What is the most likely cause of this result? ​

A) ddCs were omitted from the sequencing reaction.
B) The cytosine deoxyribonucleotides were omitted from the sequencing reaction.
C) DNA polymerase was omitted from the sequencing reaction mix.
D) The ddG fluorescent tags were degraded.
E) There is no cytosine in this DNA molecule.