You are joining a divided highway from an on ramp with a loaded trailer, and the traffic in the right lane is moving at highway speed.
- Stop at the end of the ramp and wait for a gap you can pull out into
- Build what speed you can on the ramp and pick a gap far bigger than a car would need, because you accelerate slowly
- Move out as soon as you reach the end of the ramp, since the traffic on the highway has to let you in
- Drive along the shoulder past the merge until a gap appears
The answer is B
The traffic already on the highway has the right of way, so joining it is your problem to solve rather than theirs. A loaded vehicle takes far longer to reach highway speed than a car, which means the gap you need is longer than the one that looks about right from the driving seat. Stopping at the end of the ramp is worse again, because you then start the whole acceleration from nothing with traffic arriving behind you.
Alberta Driver's Guide (Government of Alberta)

