The Gal4p Protein Can Simultaneously Regulate the Five Genes Involved

The Gal4p protein can simultaneously regulate the five genes involved in galactose metabolism in Saccharomyces cerevisiae, despite binding to a specific 17-base pair upstream activator sequence (UAS) , because

A) it binds to the UAS of the first gene, triggering a regulatory gene cascade that quickly increases transcription of the other four genes.
B) the five genes are grouped into a single cistron and are regulated by one UAS.
C) each of the five genes has the same UAS.
D) each of the five genes has its own UAS to bind the Gal4p-Gal80p complex to initiate transcription.
E) it is not the binding of the Gal4p protein to the UAS that is involved in regulation, but the protein synthesised from the UAS.