The Accompanying Table Lists Several Genotypes Associated with the Lac

The accompanying table lists several genotypes associated with the lac operon in E.coli.For each,indicate with a "+" or a "-" whether β-galactosidase would be expected to be produced at induced levels.
$\begin{array}{llcc}&\beta \text {-galactosidase production }\\\underline { \text { Genotype } } &\underline {\text { No Lactose \quad \quad With Lactose}} \\(a) \quad I^{+} O+Z+/ F^{\prime} I+O+Z+&\\(b) \quad I-O c Z-/ F^{\prime} I-O c Z- \\(c)\quad I{s} I-O c Z+/ F^{\prime} I-O+Z+ \\(d) \quad Is Oc Z-/F'Is O+Z+\\\end{array}$

$\begin{array}{l}I^{+}=\text {wild-type repressor } \\I^{-}=\text {mutant repressor (unable to bind to the operator) } \\I^{s}=\text { mutant repressor (insensitive to lactose) } \\O^{+}=\text {wild-type operator } \\O \mathcal{C}=\text { constitutive operator (insensitive to repressor) }\end{array}$