Answer:
The correct answer is - on, actively synthesize.
Step-by-step explanation:
The arg operon is a negative regulator that releases or regulates the production of arginine in only the presence of arginine. Attaching the arginine to the arginine repressor protein causes the repressor to bind to the operator sequence.
When a cell is growing actively this operon is on and the synthesis of arginine in this cell is continuous. Arginine induces a conformational change in the protein structure.