English Idioms — Choose the correct meaning. Sentence: It is no longer easy to strike gold in Shakespeare's research since much work has already been done on him.

Introduction / Context:
“Strike gold” is used metaphorically in academic and journalistic writing to mean discovering something especially valuable—new data, a novel argument, or a unique insight. The sentence clarifies the domain (Shakespeare studies) and explains why it is difficult now (much prior work), which underscores the research metaphor rather than literal treasure hunting.

Given Data / Assumptions:

• Idiom: strike gold (figurative use).
• Domain: academic research.
• Constraint: field saturation due to extensive scholarship.

Concept / Approach:
Among the options, only option D explicitly mentions “valuable line of argument or information,” matching research outcomes. Options A–C push literal or irrelevant readings (geographic location, physical gold, or a specific word in texts).

Step-by-Step Solution:

Verification / Alternative check:
Paraphrase: “It is no longer easy to uncover valuable new arguments or information in Shakespeare studies …” This preserves the logic and tone of the original sentence.

Why Other Options Are Wrong:

• Hit a golden spot: Vague and literal-leaning; not scholarly.
• Come across gold: Literal material gold; irrelevant to research.
• Come across the word 'gold': Humorous red herring; not intended.

Common Pitfalls:
Forgetting that many mining metaphors in English (“strike gold,” “goldmine of data”) refer to intellectual discovery, not physical treasure.

Final Answer:
Uncover or find a valuable line of argument or information