What does the word "spurious" signify?

The word "spurious" is commonly used to describe something that appears to be genuine or valid but is actually false or deceptive. Therefore, the significance of "spurious" aligns perfectly with the meaning of plausible but false. This term can refer to arguments, claims, or even objects that may seem plausible on the surface yet lack authenticity or truth upon closer inspection.

In contrast, the other choices do not accurately capture the meaning of "spurious." "Authentic and true" directly opposes the concept of spuriousness, as it represents genuine and reliable qualities. "Unusual and unique" does not relate to authenticity or deception; it describes something that stands out but does not inherently indicate truthfulness or validity. Finally, "ambiguous and unclear" suggests a lack of clarity, which does not reflect the essence of spuriousness, as spurious items can sometimes appear clear or convincing while still being false. Thus, the best choice that encapsulates the meaning of "spurious" is the option that connotes something that is seemingly credible yet fundamentally untrue.