Explanation
Correct answer: D.
Choice D is the best answer. "Moreover" logically signals that the information in this sentence—that Franklin stamped imprints on paper money to make forgery more difficult—adds to the previous information by describing Franklin’s other strategy for combatting forgers: weaving materials into the paper used for printing money.
Why the other choices are wrong
Choice A
Choice A is incorrect because "specifically" illogically signals that the information in this sentence provides specific, precise details elaborating on the previous information about Franklin’s other strategy for combatting forgers (weaving materials into paper). Instead, this information about stamping imprints on money adds new information.
Choice B
Choice B is incorrect because "that said" illogically signals that the information in this sentence is an exception to the previous information about Franklin’s other strategy for combatting forgers (weaving materials into paper). Instead, this information about stamping imprints on money adds new information.
Choice C
Choice C is incorrect because "for example" illogically signals that the information in this sentence serves as an example of the previous information about Franklin’s other strategy for combatting forgers (weaving materials into paper). Instead, this information about stamping imprints on money adds new information.