Final answer:
The exact volume of water a horse swallows in each gulp is not provided in the options, but based on a horse's size, it likely swallows more than a half-pint of water in each gulp. The information given about sugar in water glasses and human urine output is not directly relevant to answering the question on the horse's gulp volume.
Step-by-step explanation:
The amount of water a horse generally swallows in each gulp is not specified in the provided choices of more than a half-pint, exactly a half-pint, slightly less than a half-pint, or two half-pints. However, considering the size of a horse and its physiology, it is likely that a horse swallows more than a half-pint of water in each gulp. Horses have a large body mass and require a significant amount of water for hydration, so their gulp volume would reflect this need.
The comparison using glasses of water mixed with sugar is used to explain how solute volume affects the amount of solvent (water) in a given volume. This does not directly relate to the volume of water a horse consumes in a gulp. As for the urine output information, after drinking a large glass of water, most humans start to see an increase in urine output within about 30 minutes. While this information is related to water consumption, it does not directly answer the question about the volume of water a horse swallows per gulp.