The correct answer is option letter C (a problem to resolve). By definition, to have an axe to grind is <u><em>to have a complaint or dispute that one feels compelled to discuss</em></u>. For instance, “<em>I think the boss </em><u><em>has a bit of an axe to grind</em></u><em> with the employees over the way the account was handled</em>”. Here the phrase means that the boss has a problem to work out with the employees. It is difficult to trace the origin of the phrase, but it is commonly attributed to <em>Benjamin Franklin</em>; however, other opinions point to another author who also lived in Pennsylvania, USA.