In the following question, four alternatives are given for the idiom/phrase in bold and italics in the sentence. Choose the alternative which best expresses the meaning of idiom/phrase.
It is no longer easy to strike gold in Shakespeare's research since much work has already been done on him.
Hit a golden spot
Come across gold
Come across the word "gold"
Uncover or find a valuable line of argument or information
Correct answer is D
No explanation has been provided for this answer.