As is is cleared from the figure that when lactose is absent, the lac repressor binds tightly to the operator. It gets in RNA polymerase's way and prevent transcription.
Lac repressor does inhibit expression of the lac operon when there is no lactose present (because it's a waste to make these proteins when there's no lactose around), however, the statement above is false because the lac repressor binds to the OPERATOR site, not the promoter.
The answer is D. A, B, and C all use photosynthesis, and make their own energy. A cougar relies on killing other animals to get energy. I hope this helps!
