How many grams are equivalent to 1 kilogram?

One kilogram is defined as being equal to 1000 grams. This relationship is fundamental in the metric system, where the prefix "kilo-" represents a factor of 1000. Therefore, when converting kilograms to grams, you multiply by 1000. This makes it clear that 1 kilogram is precisely equivalent to 1000 grams, which is why the answer is correct. The other options reflect quantities that do not equate to one kilogram and illustrate the importance of understanding metric conversions.