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.
In the attachment are some examples:
First it's can not be biosynthesis because it is taking in food molecules means it cannot synthesisi its food
Second nutrition is the process to take nutrients
Third absorption means to absorb but here cell does phagocytosis and pinocytosis
Forth digestion obviously when an organism eats something it have to digest it and it it is its capability.... and so far as I think Digestion should Ben your answer!
So for the answer for this one is going to be d