Questions: According to my friend, a coin collector, a number of people are seeking Liberty Head nickels minted in 1883.

The answer is D: Liberty Head nickels are sought by a number of people.

Explanation for each option:

(A) [NO CHANGE]: "a number of people are seeking Liberty Head nickels" - This option is grammatically correct, but it is less concise compared to option D.

(B) "a number of people is seeking Liberty Head nickels" - This option is incorrect because "a number of people" is a plural subject, and it should be followed by "are" instead of "is."

(C) "Liberty Head nickels are being sought by a number of people, they were" - This option is incorrect because it is a run-on sentence. The comma does not properly connect the two independent clauses.

(D) "Liberty Head nickels are sought by a number of people" - This option is correct. It is concise and grammatically accurate, making it the best choice.