Explanation:

- The definition “A Wagering Agreement is a promise to give money or money’s worth upon the determination or ascertainment of an uncertain event” is widely attributed to Pollock.

- Anson: Famous for writings on Contract Law, but not specifically for this definition.

- Pollock: Correct. He has defined wagering agreements very similarly in legal literature.

- Drucker: Not known in the context of contract law; more associated with management.

- Cockburn: Not linked directly with this statement in legal texts.

The correct answer is:

Option:2, Pollock