Because people sort things by what is written on the outside, the Troy-bilt section would be best.
There is only 1 forum and the subsections are just there to make searching easier by grouping post together by subject rather by the date.
However what is handy is for you to be very clear . Trimmer ? line trimmer or push mower ?
Next please try to remember you have the item right in front of your face.
Our noses are only in front of a screen with nothing to go on but the words you type.