Final answer:
A Euro-metric tire size among the given options is '225/50R16 92', identified by the absence of a preceding letter and a two-digit aspect ratio.
Step-by-step explanation:
The example of a Euro-metric tire size from the options provided is 225/50R16 92. Euro-metric tire sizes are marked without a preceding letter and traditionally use a two-digit aspect ratio.
On the other hand, U.S. tire sizes, such as P-metric and LT-metric, begin with 'P' for passenger vehicles or 'LT' for light trucks, indicating their intended use, and can use either two-digit or three-digit aspect ratios.
For example, 'P225/50R16 91S' would be a U.S. P-metric size, and 'LT245/75R16' would be a U.S. LT-metric size designed for light trucks.