Among the Mechanisms Escherichia Coli Has for the Control Of \beta

Among the mechanisms Escherichia coli has for the control of $\beta$ -galactosidase production is

A) that the combination of cAMP and CAP restricts the ability of RNA polymerase to function.
B) the presence of the lac operon necessary for the production of the enzyme to be halted reducing overproduction.
C) that glucose must be absent and galactose present for the production to begin.
D) that the speed with which the enzyme is produced is accelerated by the presence of both galactose and glucose.