If line B is not getting hit in 3 business days, then may be its not correct to be on long side.
if unnamed line getting hit in mentioned time, then may be its not correct to be on short side.
If line A is getting hit in mentioned time, then takes some time in retracing and check if it pass thru above the line A to be on long side.
Note the word: 'May be' (Probables)
PS: Not all lines are trendline here.