You don't have any choices here, so we can just find the range of the answer. Then, you can select the correct answer.
The probability must be greater than 66.67%: P > 66.67% (or 2/3).
The chance of rain on Friday is 2/3. If it is more likely on Saturday, then it must be more than 2/3. 2/3 is about 66.67% percent.
