Final answer:
The preferred system of measurement at present is the metric system, which is used internationally and in scientific contexts due to its simplicity and standardization based on multiples of ten.
Step-by-step explanation:
The system of measurement that is preferred at the present time is the metric system. This system is the standard in science and is used by most countries outside of the United States. The metric system is advantageous because it is based on multiples of ten, making conversions simpler than other methods of measurement. Fundamental units in the metric system include the meter for length, the liter for volume, and the gram for mass. In contrast, the United States commonly uses the customary system, also known as the Imperial System, which includes units such as feet, inches, pounds, cups, and gallons. While the customary system is prevalent in everyday life in the U.S., when it comes to scientific and international applications, the metric system is preferred due to its ease of use and universal acceptance. Therefore, the correct answer is B. metric system.