Correct Answer: A

Rationale: To convert milligrams to micrograms, you need to multiply by 1000, not 10000. Therefore, 0.025 mg is equal to 25 mcg. The correct conversion is obtained by recognizing that 1 milligram (mg) is equal to 1000 micrograms (mcg). Choices B, C, and D are incorrect because they do not correctly convert milligrams to micrograms. Choice B is 10 times the correct answer, choice C is 100 times less, and choice D is 100 times less than the correct conversion.

Correct Answer: A

Rationale: To convert milligrams to micrograms, you need to multiply by 1000, not 10000. Therefore, 0.025 mg is equal to 25 mcg. The correct conversion is obtained by recognizing that 1 milligram (mg) is equal to 1000 micrograms (mcg). Choices B, C, and D are incorrect because they do not correctly convert milligrams to micrograms. Choice B is 10 times the correct answer, choice C is 100 times less, and choice D is 100 times less than the correct conversion.

Correct Answer: B

Rationale: The correct answer is B: '0.001 m.' The prefix 'milli' represents a factor of 10^-3, which means one millimeter (mm) is equivalent to 0.001 meters (m). Therefore, 1 mm is equal to 0.001 m. Choice A, '0.01 m,' is incorrect as it represents 0.01 meters, not 0.001 meters. Choice C, '0.1 m,' is incorrect because it stands for 0.1 meters, which is 10 times greater than 1 mm. Choice D, '1 m,' is incorrect as it represents 1 meter, which is 1000 times greater than 1 mm.

Correct Answer: A

Rationale: 0.05 mg is equivalent to 50 mcg because 1 mg is equal to 1000 mcg. To convert milligrams to micrograms, you need to multiply by 1000. Therefore, 0.05 mg x 1000 = 50 mcg. Choices B, C, and D are incorrect because they do not correctly convert milligrams to micrograms. Option B (500 mcg) would be the result if the conversion was done incorrectly by adding an extra zero, while options C (5 mcg) and D (0.5 mcg) are incorrect due to miscalculating the conversion factor.

Correct Answer: D

Rationale: The correct answer is D: Exact Equivalent. The expression 1 inch = 2.54 cm is a direct and precise conversion between inches and centimeters, making it an exact equivalent. It is not related to the Law of Conservation of Units (A) as this principle pertains to the conservation of physical quantities in a system. The International Yard (B) is a unit of measurement, but it is not the term for the given expression. Similarly, while the conversion factor in the expression is standard, it is specifically an exact equivalent and not just a general standard conversion factor (C). Therefore, D is the most appropriate term to describe this specific conversion relationship.