Correct Answer: A

Rationale: The correct answer is A: 298.15 K. The conversion from Celsius to Kelvin is K = C + 273.15. Therefore, 25°C is equivalent to 298.15 K, as 25 + 273.15 = 298.15. Choice B, 273.15 K, is the freezing point of water in Kelvin, not the equivalent of 25°C. Choice C, 250 K, and Choice D, 25 K, are incorrect conversions and do not align with the correct formula for converting Celsius to Kelvin.

Correct Answer: C

Rationale: To convert kilograms to grams, you need to multiply by 1000 since there are 1000 grams in a kilogram. Therefore, 5 kilograms is equal to 5,000 grams. Choices A, B, and D are incorrect because they do not correctly convert the given amount of kilograms to grams.

Correct Answer: A

Rationale: To convert grams to milligrams, you need to multiply by 1000, not 10000. Therefore, to convert 0.04 grams to milligrams, you multiply 0.04 by 1000, which equals 40 mg. Choice A (40 mg) is the correct answer. Choice B (4 mg) is incorrect as it represents converting 0.004 grams to milligrams. Choice C (400 mg) is incorrect as it is 10 times the correct conversion. Choice D (0.4 mg) is incorrect as it is 10 times smaller than the correct conversion.

Correct Answer: B

Rationale: The correct answer is B: 1000 meters. One kilometer is equivalent to 1000 meters. Therefore, 1000 meters is the accurate conversion from kilometers to meters. Choices A, C, and D are incorrect. Choice A (100 meters) is incorrect as it represents 1/10th of a kilometer. Choice C (500 meters) is incorrect as it is half the value of a kilometer. Choice D (2000 meters) is incorrect as it exceeds the value of a kilometer.

Correct Answer: B

Rationale: The correct answer is B: 5280 feet. One mile is equivalent to 5280 feet. This is a standard conversion that is widely known. Choice A (5000 feet) is incorrect as it is not the exact conversion of a mile. Choice C (5300 feet) and choice D (5500 feet) are also incorrect as they do not represent the accurate conversion from miles to feet.