Choose the option which can be substituted for the given words/sentence. One who pretends to have knowledge or skills that they do not actually possess.

Charlatan refers to a fraud or impostor—someone who falsely claims to have knowledge or expertise in a certain field, often to deceive others. Cynic is a person who believes that people are motivated purely by self-interest and often doubts sincerity. Pragmatist is someone who is practical and focused on results rather than ideals. Idealist is a person guided by high principles or lofty goals, often unrealistic in practical matters. Since "Charlatan" best describes a pretender of knowledge or skill, it is the most  appropriate answer.