The is conflicting info on this site as to how I account for my child's T4A(P) benefit. File their own return or put on my return under dependant deductions NI?

I seem to be getting conflicting answers on the site about how to deal with my child's T4A(P) slip. It is their only income/benefit. Do I:

1. File a separate return for him?

2. Just ignore it, as it is very little income?

3. Add it to the Deductions -> Additional Dependant Info -> Net Income? This doesn't seems right as it references that I would have a T1 for him. 

Please advise