A partial diploid of genotype I^S P⁺ O⁺ Z⁺ / I⁺ P⁺ O⁺ Z^- will show:

A)inducible production of repressor.
B)inducible production of $\beta$ -galactosidase.
C)constitutive production of $\beta$ -galactosidase.
D)no production of $\beta$ -galactosidase.
E)constitutive production of lactose.