Correct option is C
The degree of polymerization, which is defined as the average number of monomer residues per polymer molecule. This quantity is the ratio of the initial concentration of A, [A]o , to the concentration of end groups, [A], at the time of interest, because there is one -A group per polymer molecule. For example, if there were initially 1000 A groups and there are now only 10, each polymer must be 100 units long on average. Because we can express [A] in terms of p, the average number of monomers per polymer molecule, <n>, is
This result is illustrated in figure. Expressing p in terms of the rate constant k
The average length grows linearly with time. Therefore, the longer a stepwise polymerization proceeds, the higher the average molar mass of the product.
