He paid the dining bill . . . . . . . . a credit card. A. for B. in C. by D. with

The correct answer is: with.

The preposition “with” is used to indicate the means or instrument by which something is done. In this case, the speaker is indicating that the man paid the bill using a credit card.

The other options are incorrect because they do not make sense in the context of the sentence.

• “For” is used to indicate the purpose or reason for something. In this case, the speaker is not indicating the purpose for which the man paid the bill.
• “In” is used to indicate a location or position. In this case, the speaker is not indicating the location where the man paid the bill.
• “By” is used to indicate the agent or cause of something. In this case, the speaker is not indicating the agent who caused the man to pay the bill.