In Catabolite Repression Systems of Some Gram-Positive Bacteria,such as Bacillus

In catabolite repression systems of some Gram-positive bacteria,such as Bacillus subtilis,transcription of catabolic operons is regulated by CcpaA (catabolite control protein A) rather than cAMP.Propose a hypothesis to explain the preferential use of glucose in the presence of a second sugar such as sucrose by Bacillus subtilis.

A) CcpaA acts as a repressor of sucrose operon genes in Bacillus subtilis when both sugars are present.
B) CcpaA acts as an inducer of sucrose operon genes in Bacillus subtilis when both sugars are present.
C) CcpaA acts as a repressor of sucrose operon genes in Bacillus subtilis when lactose,but not glucose,is present.
D) CcpaA acts as an inducer of sucrose operon genes in Bacillus subtilis when glucose,but not lactose,is present.