Explanation:

- The case Boulton v Stone (1951) involved a cricket ball hit out of a ground, injuring a passerby.

- The main legal issue was about negligence and if the defendants had breached their duty of care.

- The House of Lords held that they were not negligent because such an event was extremely rare and precautions were already taken.

- This case is famous for clarifying the standards of negligence, especially the "reasonable man" test.

- It does not deal with liquidated damages (fixed damages agreed upon in a contract).

- Liquidated damages are not relevant here.

- Negligence and breach of duty standards of a reasonable man are both closely related, but the famous principle is the latter.

Correct Answer:

Option:3, Breach of duty standards of a reasonable man