Question

1. if you were traveling out the united states, which system of measurement would you need to use?

us customary system
si customary system
metric system
measurement system

Explanation:

The US customary system is mainly used in the United States. The "SI customary system" is not a standard term. The metric system (also known as the International System of Units, SI) is the standard system of measurement used in most countries outside the US. "Measurement system" is a general term and not a specific system for this context. So when traveling outside the US, the metric system is used.

Answer:

C. metric system