Which of the following best represents an immoral person?

An unscrupulous person is one who lacks moral principles or a sense of what is right and wrong. This characteristic highlights a disregard for ethical standards and a willingness to engage in dishonest or manipulative behavior. Such individuals often prioritize their own interests above the welfare of others and are willing to exploit situations or manipulate people to achieve their goals.

In the context of the other choices, schemes could refer to plans that may be either moral or immoral, but they do not inherently imply a lack of morality. Syndrome refers to a collection of symptoms or conditions and does not pertain to moral character. Drudgery involves tedious or hard work, which also does not directly relate to a person's moral standing. Therefore, the best representation of an immoral person in this context is found in the term "unscrupulous," as it succinctly conveys the essence of lacking moral integrity.