Correct Answer: D

Rationale: The correct answer is D: 1,000 µg. To convert milligrams to micrograms, you need to multiply by 1,000 because there are 1,000 micrograms in 1 milligram. Choices A, B, and C are incorrect because they do not correctly convert milligrams to micrograms. 1 milligram is equal to 1,000 micrograms, making choice D the right answer.

Correct Answer: B

Rationale: The metric system was developed in France during the 1790s as a standardized system of measurement. This choice is correct because the metric system originated in France. Germany, Italy, and Spain did not play a role in the development of the metric system, making choices A, C, and D incorrect.

Correct Answer: A

Rationale: The mnemonic 'King Hector Died By Drinking Chocolate Milk' aids in recalling metric prefixes in order: kilo-, hecto-, deca-, base (meter, liter, gram), deci-, centi-, milli-. Choice B does not provide a relevant mnemonic for metric conversions. Choices C and D do not offer a helpful phrase for remembering metric prefixes, making them incorrect.

Correct Answer: B

Rationale: The correct answer is B: Liters. In the metric system, liters are the base unit for liquid volume. Milliliters, though a metric unit, are a smaller unit of volume and not the base unit. Gallons, on the other hand, are part of the imperial system and not a metric unit for volume. Option D is a duplicate of option B, making it incorrect.

Correct Answer: B

Rationale: The correct answer is B: 0.1 cm. One millimeter is equal to 0.1 centimeters, not 1/100th cm as mentioned in choice A. Choice C, 1 cm, is incorrect as a millimeter is smaller than a centimeter. Choice D, 10 cm, is incorrect as it incorrectly magnifies the conversion, making a millimeter larger than a centimeter. Therefore, the accurate conversion is that one millimeter equals 0.1 centimeters.