The lac repressor prevents the lac genes in the DNA of E. coli from being expressed most of the time. The answer to your question is A. I hope this is the answer that you are looking for and it comes to your help.
1.8.99999999.0
2.10,000,000,000,000,000,000,000,000,000 6,000,000,000,000,000,000, 3 billion 9 million 60,000 I'm sorry I tried♂️