Lac Operon Questions

Select the two correct statements about the lac operon:(a) Glucose or galactose may bind with the repressor and inactivate it.(b) In the absence of lactose the repressor binds with the operator region.(c) The $z$ -gene codes for permease.(d) This was elucidated by Francois Jacob and Jacques Monod.

Which enzyme/s will be produced in a cell in which there is a non-sense mutation in the lac Y gene?