Answer:
2nd Box
4th Box
Explanation:
The factors of a graph is whenever the graph touches the x-axis. 
A standard factor has the format (x-a), where a is the x-value. 
From the graph, we can see that the graph touches the x-axis at x=3 and at x=4. 
Therefore, this means that our factors are: 

Simplify: 

Check the second and fourth boxes. 
And we're done!