In a free radical polymerisation the rate of polymerisation is $R_p=k[\mathrm{M}][\mathrm{I}{]}^{1/2}$ and the average degree of polymerisation is proportional to $[\mathrm{M}]/[\mathrm{I}{]}^{1/2}$, where I is the initiator. At fixed monomer concentration and temperature, the initiator concentration is made four times larger. Then

1. A$R_p$ becomes four times and the average degree of polymerisation becomes one quarter
2. B$R_p$ becomes twice and the average degree of polymerisation becomes half
3. C$R_p$ becomes twice and the average degree of polymerisation becomes twice
4. D$R_p$ becomes half and the average degree of polymerisation becomes twice