Explanation:

- Option 1: Holland

- Sir Thomas Erskine Holland was a British jurist.

- He was known for his work on international law and legal theory.

- He had different views on the nature of law but did not define jurisprudence in the way mentioned.

- Option 2: Pound

- Roscoe Pound was an American legal scholar.

- Known for his work on sociological jurisprudence.

- He viewed law through the lens of its social purposes.

- Option 3: C.K. Allen

- Correct Answer: C.K. Allen was a legal scholar.

- He defined jurisprudence as "the scientific synthesis of the essential principles of law."

- Believed in connecting legal developments with their underlying principles.

- This is your correct answer.

- Option 4: Ihering

- Rudolf von Jhering was a German jurist.

- Known for his emphasis on the purpose of law.

- Did not use the specific phrase mentioned but focused on law's goals.