His oily tongue has won him promotion. A. soft speech B. word power C. flattery D. fluency in speech

The correct answer is C. flattery.

Flatter is to praise someone in an excessive way in order to gain their favor. In the sentence, “His oily tongue has won him promotion,” the speaker is implying that the person has been promoted because of their ability to flatter others.

Soft speech is speech that is gentle and soothing. Word power is the ability to use words effectively. Fluency in speech is the ability to speak smoothly and easily.

While soft speech, word power, and fluency in speech can all be helpful in gaining promotion, they are not the same as flattery. Flattery is specifically the act of praising someone in an excessive way in order to gain their favor.