What does "Sobriety" signify?

The term "sobriety" primarily refers to a state of being sober, which encompasses the absence of intoxication. In a broader context, it signifies a quality of seriousness, calmness, and thoughtful behavior. This aligns with the second option, which captures the essence of being quiet or serious.

In contrast, the other options don't accurately reflect the meaning of sobriety. A joyful demeanor suggests lightheartedness and cheer, which runs counter to the seriousness implied by sobriety. A state of active engagement indicates a lively or energetic involvement, rather than the restrained and serious manner associated with sobriety. Being carefree and relaxed conveys a sense of freedom from worry, again diverging from the more measured and serious tone that sobriety encapsulates. Therefore, recognizing sobriety as a state of being quiet or serious helps to ground its meaning in both its literal and figurative uses.