B is correct. Hope this helps
For this case, what you should see is where the graph cuts the x-axis.
Notice that the graph cuts to the x axis in three different points.
Then the value of x that is in the domain of the function in this case is:
x = 1
For this value of x the function is zero.
Answer:
x = 1
Convert them all to decimals then sort them from least to greatest:

,

,

,3.6