'Mountebank' refers to a person who deceives others, especially in order to trick them out of money; a fraud, charlatan, or hypocrite. It comes from Italian words meaning 'mount' + 'bench' - referring to quack doctors who would stand on benches to sell fake medicines. Option C 'a hypocrite' is the correct synonym. Options A (hillock), B (small bank), and D (monk) are either literal misinterpretations or completely unrelated meanings.