From the given points on the graph we can find which function represents this graph.
A point on the graph is (3, 1). This means if we substitute x = 3 the answer must be 1.
The property of log is that
![log_(a)(a)=1](https://img.qammunity.org/2019/formulas/mathematics/middle-school/768j77c8fayrgat2ivhfz928w5ywnb7ezq.png)
This suggests, if the base of log is equal to the number for which we are finding the log, the answer must be 1.
So, in this case we have:
![log_(a)(3)=1](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xob9aa1zt3ihetbkxlgt39he34x2jwjvxr.png)
Since the answer is 1, the base of log must be 3.
In the given options, only option 3rd is with base 3.
So, the correct answer is option 3.