For Each of the Following E

For each of the following E. coli partial diploid strains, indicate whether expression of fi- galactosidase and permease is inducible (I), constitutive (C), or noninducible (N). Assume glucose levels are very low. Which of the strains are able to use lactose as their sole carbon source?
$$\begin{array} { | l | l | l | l | } \hline && \beta \text {-galactosidase } & \text { Permease } \\\hline \text { a. } & I ^ { s } O ^ { + } Z Y ^ { + } / I ^ { + } O ^ { C } Z ^ { + } Y & & \\\hline \text { b. } & I ^ { + } O ^ { + } Z Y ^ { + } / I ^ { + } P ^ { - } O ^ { + } Z ^ { + } Y ^ { + } & & \\\hline \text { c. } & I ^ { + } O ^ { C } Z Y ^ { + } / \Gamma O ^ { + } Z ^ { + } Y ^ { + } & & \\\hline \text { d. } & I ^ { + } O ^ { + } Z ^ { + } Y / I ^ { + } P ^ { - } O ^ { C } Z ^ { + } Y ^ { + } & & \\\hline\end{array}$$