Answer:
D) doubles the rate
Step-by-step explanation:
The given reaction is :

For the
reaction, the rate of reaction depends upon the concentration of both the
as well as the

That is the rate =
![$k[CH_3Br][OH^-]$](https://img.qammunity.org/2022/formulas/chemistry/college/6siig1y8lg5d6quvce7hpnps07hnin2nsn.png)
Now if the
becomes
, then the rate becomes double.
So the rate' is :
=
![$2k[CH_3Br][OH^-]$](https://img.qammunity.org/2022/formulas/chemistry/college/hpbrkivim8ma35zcwt9e3l734jw62jj36v.png)
= 2 x rate
Therefore, the answer is (D) doubles the rate.