Which of the following words have antonymy?

The choice of "light and dark" as having antonymy is correct because these two words represent two opposing concepts related to illumination. "Light" refers to the presence of illumination, while "dark" signifies its absence. This clear distinction is a fundamental characteristic of antonyms, where one term directly opposes the other in meaning.

In contrast, while "hot and cold" does represent opposing temperatures, it's commonly understood that these terms describe a range of temperatures rather than a strict binary opposition.

The terms "happy and joyful" are closely related and often used interchangeably in everyday language, suggesting a more nuanced distinction rather than direct opposition. Both imply positive emotional states but do not reflect a stark contrast.

"Small and little," similarly, suggest minor differences in size but are often synonymous, indicating varying degrees of size rather than opposing meanings.

Thus, "light and dark" stand out as a clear example of antonymy due to their explicit contrasting meanings.