John may be sincere, but I suspect that he has an axe to grind . This means that John has a

Analyze the question: The sentence uses an idiom, "to have an axe to grind." You are asked to choose the option that gives its meaning.

Explain the concept: To have an axe to grind means to have a private, selfish reason for doing or saying something. It describes a person who appears to be helping or giving an honest opinion but is really trying to benefit himself.

Step-by-step solution:

1. The sentence says "John may be sincere, but I suspect..." The word "but" signals a contrast. John seems sincere, yet the speaker doubts it.
2. So the idiom must mean something that goes against sincerity, which is a hidden personal interest.
3. Checking the options: • A. selfish motive: This fits. A hidden, self-serving reason contrasts with sincerity. • B. different opinion: Having a different opinion does not make someone insincere. • C. matter to attend to: This takes "axe to grind" too literally, as if there were a task to do. • D. solution to the problem: This has no connection to the idiom.

Answer: The correct option is A. selfish motive.

Tip: For idiom questions, look for linking words like "but," "although," and "however." They show whether the idiom has a positive or negative meaning. Also remember that "axe to grind" is always about a hidden personal interest. Picture someone sharpening his own axe for his own benefit.