They faced harch conditions and struggled throughout the trip.
A written legal code would be am improvement over an oral set of laws because citizens may forget laws, depending on how much there are. Having them written, where everyone can read it, may help them better understand and remember the acts/laws.
The higher teaching is the doctrine of the Four Noble Truths and the Path, and this is the Buddhist doctrine of salvation. When a being decides to turn his aspirations in the direction of the Path, then his efforts culminate, not in heaven, but in a state which is outside the whole system of samsära.
The answer is the first one, A