Instead of building the full order first, check each option (each hill as a candidate for southernmost) against all five clues and see which one survives.
Only the H3 case satisfies clues (i) through (v) together, without any contradiction.
Let's summarize:
The southernmost hill is H3, option (C).
Statement: All flowers are beautiful. Some beautiful things are fragile.
Conclusion I: Some flowers are fragile.
Conclusion II: All beautiful things are flowers.